Understanding the Copassivation Effect of Cl and Se for CdTe Grain Boundaries

Shah, Akash; Nicholson, Anthony P.; Fiducia, Thomas; Abbas, Ali; Pandey, Ramesh; Liu, Junliang; Grovenor, C.R.M.; Walls, John M.; Sampath, Walajabad S.; Munshi, Amit

doi:10.1021/acsami.1c06587

Cited by 21 publications

(9 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…DFT-1/2 has also been applied to diamond [179], Gecontaining semiconductors [180,181], SiC [182,183], III-V semiconductors , spinel nitrides [217], EuS [218], MgTe [219], doped K 0.5 Na 0.5 NbO 3 [220,221], halide perovskites [222][223][224][225][226][227][228][229][230][231][232][233][234][235], II-VI semiconductors [236][237][238][239][240][241][242][243][244], WO 3 [245], LiGa 5 O 8 [246], silicon surfaces [247][248][249][250][251][252][253][254][255], alkaline earth fluorides [147], Ca oxides [256], SnO 2 [257], Be-VI polymorphs…”

Section: Bulk Electronic Band Structure Calculationmentioning

confidence: 99%

DFT-1/2 and shell DFT-1/2 methods: electronic structure calculation for semiconductors at LDA complexity

Mao

Yan

Xue

et al. 2022

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

It is known that the Kohn-Sham eigenvalues do not characterize experimental excitation energies directly, and the band gap of a semiconductor is typically underestimated by local density approximation (LDA) of density functional theory (DFT). An embarrassing situation is that one usually uses LDA+U for strongly correlated materials with rectified band gaps, but for non-strongly-correlated semiconductors one has to resort to expensive methods like hybrid functionals or GW. In spite of the state-of-the-art meta-GGA functionals like TB09 and SCAN, methods with LDA-level complexity to rectify the semiconductor band gaps are in high demand. DFT-1/2 stands as a feasible approach and has been more widely used in recent years. In this work we give a detailed derivation of the Slater half occupation technique, and review the assumptions made by DFT-1/2 in semiconductor band structure calculations. In particular, the self-energy potential approach is verified through mathematical derivations. The aims, features and principles of shell DFT-1/2 for covalent semiconductors are also accounted for in great detail. Other developments of DFT-1/2 including conduction band correction, DFT+A-1/2, empirical formula for the self-energy potential cutoff radius, etc., are further reviewed. The relations of DFT-1/2 to hybrid functional, sX-LDA, GW, self-interaction correction, scissor’s operator as well as DFT+U are explained. Applications, issues and limitations of DFT-1/2 are comprehensively included in this review.

show abstract

Section: Bulk Electronic Band Structure Calculationmentioning

confidence: 99%

DFT-1/2 and shell DFT-1/2 methods: electronic structure calculation for semiconductors at LDA complexity

Mao

Yan

Xue

et al. 2022

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…The detailed cell architecture and materials of the devices can be found in refs , , . The substrate used here is NSG TEC10 soda lime glass coated by fluorine-doped tin oxide (FTO).…”

Section: Methodsmentioning

confidence: 99%

Microscopy Visualization of Carrier Transport in CdSeTe/CdTe Solar Cells

Xiao

Jiang

Nardone

et al. 2022

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

Solar cells are essentially minority carrier devices, and it is therefore of central importance to understand the pertinent carrier transport processes. Here, we advanced a transport imaging technique to directly visualize the charge motion and collection in the direction of relevant carrier transport and to understand the cell operation and degradation in state-of-the-art cadmium telluride solar cells. We revealed complex carrier transport profiles in the inhomogeneous polycrystalline thin-film solar cell, with the influence of electric junction, interface, recombination, and material composition. The pristine cell showed a unique dual peak in the carrier transport light intensity decay profile, and the dual peak feature disappeared on a degraded cell after light and heat stressing in the lab. The experiments, together with device modeling, suggested that selenium diffusion plays an important role in carrier transport. The work opens a new forum by which to understand the carrier transport and bridge the gap between atomic/nanometer-scale chemical/structural and submicrometer optoelectronic knowledge.

show abstract

“…[5] This allowed for bandgap engineering and led to significant boosts in current density, carrier lifetime, and deep-level defect passivation. [6][7][8][9][10] The final 0.5% improvement resulted from a shift in doping chemistry from Cu, which has largely limited absorber hole density to mid 10 14 cm −3 , to group V dopants ("GrV", e.g., As, P), which has enabled carrier concentrations >10 16 cm −3 in polycrystalline DOI: 10.1002/advs.202309264 devices. [11][12][13] As absorber hole density increases, theoretical studies have shown recombination at or near the front interface becomes limiting.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Sub‐Bandgap Emission and Unexpected n‐Type Behavior in Undoped Polycrystalline CdSe_xTe_1‐x

McGott,

Johnston,

Jiang

et al. 2024

Advanced Science

View full text Add to dashboard Cite

Se alloying has enabled significantly higher carrier lifetimes and photocurrents in CdTe solar cells, but these benefits can be highly dependent on CdSexTe1‐x processing. This work evaluates the optoelectronic, chemical, and electronic properties of thick (3 µm) undoped CdSexTe1‐x of uniform composition and varied processing conditions (CdSexTe1‐x evaporation rate, CdCl2 anneal, Se content) chosen to reflect various standard device processing conditions. Sub‐bandgap defect emission is observed, which increased as Se content increased and with “GrV‐optimized CdCl2” (i.e., CdCl2 anneal conditions used for group‐V‐doped devices). Low carrier lifetime is found for GrV‐optimized CdCl2, slow CdSexTe1‐x deposition, and low‐Se films. Interestingly, all films (including CdTe control) exhibited n‐type behavior, where electron density increased with Se up to an estimated ≈1017 cm−3. This behavior appears to originate during the CdCl2 anneal, possibly from Se diffusion leading to anion vacancy (e.g., VSe, VTe) and ClTe generation.

show abstract

Understanding the Copassivation Effect of Cl and Se for CdTe Grain Boundaries

Cited by 21 publications

References 28 publications

DFT-1/2 and shell DFT-1/2 methods: electronic structure calculation for semiconductors at LDA complexity

DFT-1/2 and shell DFT-1/2 methods: electronic structure calculation for semiconductors at LDA complexity

Microscopy Visualization of Carrier Transport in CdSeTe/CdTe Solar Cells

Investigation of Sub‐Bandgap Emission and Unexpected n‐Type Behavior in Undoped Polycrystalline CdSe_xTe_1‐x

Contact Info

Product

Resources

About

Understanding the Copassivation Effect of Cl and Se for CdTe Grain Boundaries

Cited by 21 publications

References 28 publications

DFT-1/2 and shell DFT-1/2 methods: electronic structure calculation for semiconductors at LDA complexity

DFT-1/2 and shell DFT-1/2 methods: electronic structure calculation for semiconductors at LDA complexity

Microscopy Visualization of Carrier Transport in CdSeTe/CdTe Solar Cells

Investigation of Sub‐Bandgap Emission and Unexpected n‐Type Behavior in Undoped Polycrystalline CdSexTe1‐x

Contact Info

Product

Resources

About

Investigation of Sub‐Bandgap Emission and Unexpected n‐Type Behavior in Undoped Polycrystalline CdSe_xTe_1‐x