Library · Materials, chemistry & fabrication
What Semiconductor Doping & Implantation got wrong, from 46 theses
Summary written by a model from the records below: The records detail recurring failure modes encountered when applying doping and ion implantation techniques across semiconductor and related material systems. Common issues include structural lattice degradation from high-energy or substitutional incorporation, carrier compensation, process instability, and performance drops compared to baseline methods. These records come from graduate theses, 2021 to 2025, each labeled with its degree where the repository states it, and each links to its thesis. They were extracted by language models reading the full text, so treat each as a lead to read, not a verdict.
Plus 10 problems the authors left open, listed at the end.
Failure modes, by theses reporting them
Select a mode to jump to its records.
Ion implantation and bombardment cause lattice damage, amorphization, and electrical degradation
Ion implantation and high-energy particle bombardment introduce severe structural defects, lattice disorder, or lateral straggle in semiconductor drift regions and thin layers. These damage mechanisms lead to reduced critical temperatures, carrier mobility loss, lack of thermodynamic stability, and device failure during thermal cycling.
Tried and failed
low-energy ion implantation for carrier doping applied to two-dimensional superconductor flakes. Outcome: worse than baseline. Reason: implantation reduced critical temperature instead of enhancing it, likely due to lattice damage
Modulation of superconductivity in two-dimensional materials · UT Austin · PhD
Tried and failed
blanket ion implantation and plasma exposure applied to semiconductor lateral diodes. Outcome: unstable. Reason: caused severe electrical degradation and permanent device failure upon cryogenic thermal cycling
Formation, integration, and control of semiconductor spin-defects in electronic and photonic devices · Harvard · PhD
Tried and failed
blanket hydrogen ion implantation applied to semiconductor diode devices. Reason: caused severe electrical degradation and permanent device failure upon cryogenic cooling to 4 K
Solid-State Quantum Memories for Near-Term Quantum Repeaters · MIT · PhD
Tried and failed
selective ion implantation using shadow masking applied to vertical semiconductor power field-effect transistors. Outcome: worse than baseline. Reason: insufficient metal masking or lateral implant straggle damaged the drift region, severely degrading current density
Novel Structures for Scalable Vertical Gallium Nitride Power Devices · MIT · PhD
Tried and failed
high-current focused ion beam milling applied to semiconductor nanowire composite microcapsules. Reason: ion implantation, amorphization, and melting/redeposition of delicate nanostructures caused by high beam current
Synthesizing Semiconductor Nanowires in Hollow Microcapsules via the Geode Process · Georgia Tech · PhD
Considered and rejected
Considered and rejected: Rejected ion implantation for doping Si films due to lattice damage requiring high-temperature activation and the risk of unintentionally implanting into the underlying SiC.
Microstructural and electrical characterization of Si/4H-SiC heterojunction diodes · TU Wien · PhD
Tried and failed
inductively coupled plasma dry etching applied to crystalline barrier semiconductor heterostructures. Outcome: worse than baseline. Reason: Ion bombardment damage degraded two-dimensional electron gas mobility and significantly increased sheet resistance.
DESIGN, FABRICATION, AND CHARACTERIZATION OF ALN/GAN/ALN HIGH-ELECTRON-MOBILITY TRANSISTORS · Cornell · PhD
Considered and rejected
Considered and rejected: Rejected ion bombardment (2 MeV He+) as the defect-inducing mechanism because the induced external defects lack long-term thermodynamic stability compared to chemical doping.
Low Energy Order-To-Disorder Transition Pathways In Phase-Change Nanowires · Penn · PhD
Excessive dopant concentrations cause structural disruption, clustering, and secondary phase separation
Attempting high-concentration or multi-element chemical and substitutional doping often exceeds solid solubility limits or disrupts crystalline order. This results in the formation of secondary impurity phases, dopant clustering that quenches luminescence, or blocked transport pathways that degrade conductivity and device capacity.
Tried and failed
high-concentration chemical doping applied to conjugated polymer thermoelectric materials. Outcome: worse than baseline. Reason: severe structural disruption of lamellae caused over-doping, decreasing Seebeck coefficient without increasing electrical conductivity
Examining thermal and charge transport in organic materials with pi-electron interactions · Georgia Tech · PhD
Tried and failed
monomeric hydride n-type chemical doping applied to semiconducting polymer n-doping. Outcome: worse than baseline. Reason: bulky hydride dopant was less efficient, requiring twice the concentration to match dimeric dopant conductivity
Quantifying Charge Transport in Chemically Doped Semiconducting Polymers · Georgia Tech · PhD
Tried and failed
excessive chemical dedoping of hole transport layer applied to perovskite solar cells. Outcome: worse than baseline. Reason: degraded current density, fill factor, and reduced active layer crystallinity
Fabrication and characterization of lead-free and lead based perovskite solar cells · Imperial · PhD
Tried and failed
high-concentration multi-element substitutional doping applied to high-nickel oxide cathode materials. Outcome: worse than baseline. Reason: excess dopants cause severe capacity loss and synthesis phase inhomogeneity
High-voltage oxide cathodes for high-energy-density lithium-ion batteries · UT Austin · PhD
Tried and failed
high-concentration transition metal surface doping applied to nickel-rich layered cathode materials. Outcome: worse than baseline. Reason: excess dopant content blocked lithium transport pathways and reduced electrochemically active material fraction
Understanding and addressing the rate-limiting phenomena in energy-dense lithium-ion batteries · UT Austin · PhD
Tried and failed
high-concentration substitutional cation doping applied to perovskite metal oxide nanoparticles. Reason: Dopant concentration exceeded solubility limits, forming secondary impurity phases rather than single-phase perovskite.
Study of the effect of d-block and p-block dopants on material and photocatalytic properties of srtio3 · Imperial · Doctorate
Tried and failed
transition metal dopant incorporation applied to semiconductor nanocrystals. Outcome: worse than baseline. Reason: dopant clustering caused parasitic emission and quenched excitonic photoluminescence quantum efficiency
Charge Carrier Localisation in Metal Halide Perovskites for Optoelectronic Applications · Cambridge · PhD
Tried and failed
prolonged ambient oxidative doping before metallization applied to quantum dot hole transport layers. Outcome: worse than baseline. Reason: excessive ambient exposure increased series resistance and reduced initial power conversion efficiency
The Stability of PbS Quantum Dot Solar Cells · MIT · PhD
Considered and rejected
Considered and rejected: Rejected AuCl3 doping concentrations above 10 mM and non-polar solvents because they caused graphene sheets to rupture.
Chemical approaches for improved nanoscale organic and polymer thin-film transistors (TFTs) · UT Austin · PhD
Tried and failed
increasing dopant precursor flow rate in vapor deposition applied to wide-bandgap semiconductor epitaxial thin films. Reason: excess dopant flow caused high-density parasitic surface particle formation and degraded structural quality
Hexagonal boron nitride for deep UV applications · Georgia Tech · PhD
Ineffective dopant activation and self-compensation prevent targeted carrier modulation
Certain dopant species fail to yield active carrier conduction due to deep acceptor levels, high ionization energies, or strong self-compensation effects. Consequently, materials exhibit low electrical activation, remain semi-insulating, or suffer from severe carrier freeze-out under cryogenic conditions.
Tried and failed
transition metal doping for deep level compensation applied to ferroelectric nitride thin films. Outcome: worse than baseline. Reason: dopant introduction significantly increased leakage current instead of reducing carrier conduction
TOWARD III-NITRIDE BASED FERROELECTRIC HIGH ELECTRON MOBILITY TRANSISTORS · Cornell · PhD
Tried and failed
higher-valence cation doping to suppress leakage applied to perovskite oxide thin films. Outcome: worse than baseline. Reason: donor doping introduced additional free carriers rather than compensating defects, significantly reducing electrical resistivity
Cation Site Occupancy and Defect Engineering in Perovskite Heterostructures · MIT · Doctorate
Tried and failed
beryllium doping for p-type conductivity applied to gallium nitride epitaxy. Outcome: no signal. Reason: deep acceptor energy levels and self-compensation mechanisms resulted in semi-insulating material rather than p-type conduction
Investigation Of Metal Modulated Epitaxy Grown III-Nitride High-Power Electronic And Optoelectronic Devices · Georgia Tech · PhD
Tried and failed
in situ magnesium doping during epitaxial growth applied to hexagonal boron nitride thin films. Reason: extremely low electrical activation efficiency of incorporated magnesium dopant atoms
Advancing the Integration of 2d h-BN in Optoelectronic Applications · Georgia Tech · PhD
Tried and failed
cryogenic cooling of semiconductor devices applied to wide-bandgap p-channel field-effect transistors. Outcome: worse than baseline. Reason: incomplete dopant ionization at low temperatures increased sheet and contact resistance, reducing drive current
GaN Complementary-Metal-Oxide-Semiconductor (CMOS) Technology · MIT · PhD
Considered and rejected
Considered and rejected: Rejected vertical doping-based Super Junctions in GaN due to inefficient Mg p-type doping and lack of effective implantation/regrowth.
New Technologies to Enhance the Figures-of-Merit of GaN Power Devices · EPFL · PhD
Considered and rejected
Considered and rejected: Silicon doping for n-type B-III-V alloys was rejected due to lack of dopant activation, requiring GaTe/Te evaporation instead.
III-V optoelectronic devices in the BGaInAs material system · UT Austin · PhD
Substitutional and surface doping induce structural distortion and unwanted scattering
Direct substitutional or surface-transfer doping frequently distorts crystal lattices, disrupts sp2 bonding in nanostructures, or introduces non-uniform strain. These structural perturbations degrade carrier mobility, lower thermoelectric response, or warp thin device layers compared to pristine or undoped baselines.
Lost to a baseline
Field-effect mobility of 1.5% Nb-doped p-type MoS2 (1.43 cm2V-1s-1) was lower than pristine n-type MoS2 due to lattice distortion from substitutional doping.
Towards Scalable Electronics: Synthetic 2D Materials for Large-Area 2D Circuit Integration · EPFL · PhD
Lost to a baseline
Preformed Wheland adduct complexes achieved lower electrical conductivity (~200 S cm^-1) than neat B(C6F5)3 dopant baseline (~300 S cm^-1) when doping DPP(EDOT)2-(EDOT)2.
Rational Design of Next-Generation Organic Semiconducting Materials via Electronic Structure Methods and Machine Learning · Johns Hopkins · PhD
Considered and rejected
Considered and rejected: P-doped and n-doped SOI device layers rejected in favor of undoped silicon due to doping-induced residual stress causing face sheet warping.
Stress-resilient electromagnetically actuated deformable mirror · Boston University · PhD
Considered and rejected
Considered and rejected: Rejected transition metal oxides (MoO3, V2O5) surface-transfer doping due to drastic carrier mobility degradation at high carrier densities and integration difficulty
Diamond on GaN integration for power semiconductor devices with efficient thermal management · EPFL · PhD
Considered and rejected
Considered and rejected: Rejected conventional interstitial doping to control drain electric fields because it damages the pristine CNT lattice.
Nanosystems: From the Lab to the Fab · MIT · PhD
Considered and rejected
Considered and rejected: Rejected direct substitutional doping of CNT lattice because it disrupts sp2 bonding, increases scattering, and reduces carrier mobility.
Considered and rejected
Considered and rejected: Rejected MoO3 and polymeric interlayers because MoO3 causes p-type doping/off-state degradation and polymer solvents damage the PFBT SAM.
Analysis of the Contact Resistance of Organic Thin-Film Transistors · EPFL · PhD
Tried and failed
adatom surface doping applied to 2D topological insulator stanene. Reason: Adatoms caused excessive electronic band structure disruption or unwanted metallization instead of controlled semiconducting doping
High-performance predictions of electron and phonon transport from first principles · Harvard · PhD
Doped layers introduce deep traps, parasitic absorption, and recombination centers
Incorporating specific dopants or impurity phases can create deep midgap trap states and unwanted sub-bandgap absorption rather than facilitating targeted carrier transport. These defects act as recombination centers, increasing leakage or lowering catalytic and optoelectronic efficiency.
Considered and rejected
Considered and rejected: Rejected treating third-order bulk doping models in favor of a second-order surface dopant model because bulk dopants act primarily as recombination centers.
Optimization of Photocatalytic Processes: Catalyst Design, Kinetics and Reaction Engineering · Leibniz Universität Hannover · PhD
Tried and failed
sol-gel Pechini transition metal co-doping applied to semiconductor photocatalysts. Outcome: no signal. Reason: insufficient suppression of high-valence dopant trap states that quench photoresponse
Study of the effect of d-block and p-block dopants on material and photocatalytic properties of srtio3 · Imperial · Doctorate
Tried and failed
alkali metal codoping to suppress trap states applied to transition metal doped perovskite photocatalysts. Outcome: no signal. Reason: failed to suppress midgap trap states and unwanted sub-bandgap optical absorption
Study of the effect of d-block and p-block dopants on material and photocatalytic properties of srtio3 · Imperial · Doctorate
Tried and failed
transition metal doping with high-temperature calcination applied to photocatalytic nitrogen reduction. Outcome: worse than baseline. Reason: high-temperature calcination of metal dopants lowered photocatalytic activity compared to undoped material
Influence of Carbon and Oxygen for Photocatalytic Nitrogen Fixation on Titania · Georgia Tech · PhD
Tried and failed
nonmetal doping with phosphorus applied to semiconductor photocatalysts. Outcome: worse than baseline. Reason: deep midgap states acted as electron traps rather than facilitating catalytic charge transfer
Investigating the effect of nonmetal functionalisation on the chemical, sorptive, optoelectronic and photocatalytic properties of semiconducting boron and carbon nitride materials · Imperial · Doctorate
Tried and failed
doping oxide and phosphate impurity phases applied to catalytic nitrate reduction. Outcome: worse than baseline. Reason: impurity phases decreased hydrogenation activity instead of acting as cocatalysts
Removal of nitrate with nanoscale nickel phosphides · Iowa State · PhD
Chemical and surface doping suffer from thermal instability and environmental desorption
Surface-adsorbed and chemical dopants frequently degrade or desorb when exposed to elevated temperatures, chemical processing, or solvent washing. Thermal decomposition, surface segregation, and volatile element loss lead to rapid conductivity reduction and device degradation.
Tried and failed
Electrostatic back-gating across a solid oxide dielectric applied to hole doping in 2D semiconductors. Outcome: unstable. Reason: Trapped charge accumulation and gate-dragging at the dielectric interface prevented persistent carrier doping
Structural imaging and electro-optical control of two-dimensional semiconductors · Harvard · PhD
Tried and failed
slow cooling during post-annealing thermal processing applied to inorganic perovskite solar cells. Outcome: worse than baseline. Reason: oxygen-induced surface p-doping created a charge extraction barrier at the electron transport interface
Formation pathways and phase behaviour of CsPbI2Br: toward stable and reproducible solar sells · Imperial · PhD
Tried and failed
B-site transition metal doping in perovskites applied to thermochemical water splitting redox cycling. Outcome: unstable. Reason: Doping caused surface cation segregation and volatile component loss during high-temperature cycling
Development of perovskite-like structures for hydrogen production via two-step thermochemical water splitting · Imperial · PhD
Tried and failed
transition metal chloride chemical doping applied to carbon nanotube films. Outcome: unstable. Reason: Dopant thermally decomposed and desorbed at moderate elevated temperatures, causing significant loss of electrical conductivity.
Continuous carbon nanotube films for thermoelectric applications · Imperial · PhD
Tried and failed
wet chemical gate dielectric stripping applied to epitaxial graphene electronic devices. Reason: acid etchant caused severe chemical contamination, reversed carrier doping, degraded mobility, and destroyed edge transport states
The Edge States of Epitaxial Graphene on SiC · Georgia Tech · PhD
Considered and rejected
Considered and rejected: Rejected post-doping graphene transfer because water/solvents and 180 °C adhesion annealing remove surface corona charge and HMDS layers; adopted pre-transfer ion drive-in instead.
Graphene transparent conductors for tandem photovoltaic cells · Oxford · PhD
Doping-dependent etching and structural patterning fail due to lack of selectivity or profile grading
Patterning or selectively removing semiconductor layers based on doping profiles often fails due to graded transitions or inadequate etch contrast between dopant types. Furthermore, conventional dry etching or laser-assisted doping techniques can severely degrade underlying electronic properties.
Considered and rejected
Considered and rejected: Rejected conventional dry etching or laser writing doping for P3CPT patterning due to severe degradation of polymer electronic properties.
Liquid gated organic devices for sensing applications: from transistors to single molecule break junctions · Politecnico di Torino · PhD
Tried and failed
grating coupling for surface plasmon excitation applied to diffused semiconductor junctions. Outcome: no signal. Reason: graded doping profile prevented discrete angle-dependent plasmon polariton resonance excitation
Infrared electro-optical modulators leveraging plasmonic and nonlinear materials · UT Austin · PhD
Tried and failed
dopant-selective wet chemical etching applied to n-type patterned silicon substrates. Outcome: did not generalise. Reason: phosphorus doping lacked the etch selectivity contrast observed with boron doping
Engineering a self-aligned metal-oxide-semiconductor gate stack for nano-modular device fabrication · Georgia Tech · PhD
Left open by the authors
Problems the authors named and did not get to.
Left open
Investigate fundamental mechanisms to improve etch selectivity between silicon nitride and silicon dioxide in plasma-enhanced atomic layer etching simulations. Blocker: Vague direction without specified parameter sets, chemical surface chemistries, or target selectivity thresholds
Data-driven prediction of nonequilibrium chemistry in plasma enhanced atomic layer etching of silicon nitride · UT Austin · PhD
Left open
Use ion implantation to achieve full lithiation (x ~ 1) of LixNbO2 prior to device encapsulation. Blocker: Requires a physical semiconductor fabrication facility and ion implantation equipment
Adaptive Oxide Based Low-Power Memristive Devices for Neuromorphic Computing · Georgia Tech · PhD
Left open
Perform ion implantation experiments using Ar species instead of N on PIN rectifiers to reduce reverse leakage current. Blocker: Requires a semiconductor fabrication facility, ion implanter, and characterization equipment.
Development, Fabrication and Characterization of III-Nitride Bipolar Devices: Rectifiers, Avalanche Photodiodes, and Laser Diodes · Georgia Tech · PhD
Left open
Engineer SiGe HBT device doping profiles to reduce temperature-dependent variability enhancement at cryogenic temperatures. Blocker: Requires semiconductor device fabrication facilities or proprietary TCAD process simulation tools
Using SiGe HBTs for quantum science at deep cryogenic temperatures · Georgia Tech · PhD
Left open
Experimentally implement selective boron emitter (p++/p+) structures on single-side n-TOPCon silicon solar cells. Blocker: Requires cleanroom wet chemistry, ion implantation, ALD/PECVD/LPCVD equipment, and silicon fabrication facilities.
Development of low-cost high-efficiency tunnel oxide passivated contact silicon solar cells · Georgia Tech · PhD
Left open
Experimentally characterize the trade-off between mean dose throughput and dose uniformity in ion implantation optimization. Blocker: Requires access to physical semiconductor manufacturing equipment (ion implanter) and fab facilities
Applications of Probabilistic Machine Learning Models to Semiconductor Fabrication · MIT · PhD
Left open
Investigate diode response under H implant, DI water boil, and 400 °C RTA for simultaneous T-center synthesis and contact annealing. Blocker: Requires a semiconductor fabrication and characterization wet lab (H ion implantation, rapid thermal annealing, electrical testing).
Solid-State Quantum Memories for Near-Term Quantum Repeaters · MIT · PhD
Left open
Demonstrate inverse hybrid bonding on a wafer-to-wafer testbed with etched silicon through-holes for precursor vapor transport. Blocker: Requires a semiconductor cleanroom/fabrication lab, silicon etching, and ALD/vapor-phase bonding apparatus.
Dense Interconnect and Power Delivery Technologies for 3-D Heterogeneous Integration Architectures · Georgia Tech · PhD
Left open
Develop reliable SCALES selective KOH etching on n-type phosphorus-doped Si substrates and explore pre-formed silicide contacts. Blocker: Requires a semiconductor nanofabrication cleanroom, chemical wet lab, and physical Si substrate processing.
Engineering a self-aligned metal-oxide-semiconductor gate stack for nano-modular device fabrication · Georgia Tech · PhD
Left open
Fabricate AlGaN avalanche photodiode devices on AlN substrates using nitrogen ion implantation for electrical isolation. Blocker: Requires semiconductor cleanroom fabrication equipment, MOCVD growth, and an ion implanter.
HIGH PERFORMANCE III-NITRIDE ULTRAVIOLET AVALANCHE PHOTODETECTORS · Georgia Tech · PhD
Who has worked on this
Authors of the public theses cited on this page, most-cited first.
- Dikshita Bhattacharyya · Imperial · Doctorate · 2024
Study of the effect of d-block and p-block dopants on material and photocatalytic properties of srtio3 - Madison M. Sutula · MIT · PhD · 2025
Solid-State Quantum Memories for Near-Term Quantum Repeaters - Amy C. Brummer · Georgia Tech · PhD · 2023
Engineering a self-aligned metal-oxide-semiconductor gate stack for nano-modular device fabrication - André Perepeliuc · Georgia Tech · PhD · 2025
Hexagonal boron nitride for deep UV applications - Madison Manley · Georgia Tech · PhD · 2025
Dense Interconnect and Power Delivery Technologies for 3-D Heterogeneous Integration Architectures - Esra Alhabshi · Imperial · PhD · 2025
Formation pathways and phase behaviour of CsPbI2Br: toward stable and reproducible solar sells - Aaron Mitchell Day · Harvard · PhD · 2025
Formation, integration, and control of semiconductor spin-defects in electronic and photonic devices - Joshua Andrew Perozek · MIT · PhD · 2025
Novel Structures for Scalable Vertical Gallium Nitride Power Devices - Amalie Atassi · Georgia Tech · PhD · 2025
Examining thermal and charge transport in organic materials with pi-electron interactions - Connor Ganley · Johns Hopkins · PhD · 2025
Rational Design of Next-Generation Organic Semiconducting Materials via Electronic Structure Methods and Machine Learning - J O'Sullivan · Oxford · PhD · 2025
Graphene transparent conductors for tandem photovoltaic cells - Ioanna Itskou · Imperial · Doctorate · 2024
Investigating the effect of nonmetal functionalisation on the chemical, sorptive, optoelectronic and photocatalytic properties of semiconducting boron and carbon nitride materials
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