Se alloying has enabled significantly higher carrier lifetimes and photocurrents in CdTe solar cells, but these benefits can be highly dependent on CdSe x Te 1‐x processing. This work evaluates the optoelectronic, chemical, and electronic properties of thick (3 µm) undoped CdSe x Te 1‐x of uniform composition and varied processing conditions (CdSe x Te 1‐x evaporation rate, CdCl 2 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 CdCl 2 ” (i.e., CdCl 2 anneal conditions used for group‐V‐doped devices). Low carrier lifetime is found for GrV‐optimized CdCl 2 , slow CdSe x Te 1‐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 ≈10 17 cm −3 . This behavior appears to originate during the CdCl 2 anneal, possibly from Se diffusion leading to anion vacancy (e.g., V Se , V Te ) and Cl Te generation.
McGott, Deborah L., Johnston, Steven W., Jiang, Chun‐Sheng, Liu, Tuo, Kuciauskas, Darius, Glynn, Stephen, & Reese, Matthew O. (2024). Investigation of Sub‐Bandgap Emission and Unexpected n‐Type Behavior in Undoped Polycrystalline CdSe <sub>x</sub> Te <sub>1‐x</sub>. Advanced Science, 11(29). https://doi.org/10.1002/advs.202309264
McGott, Deborah L., Johnston, Steven W., Jiang, Chun‐Sheng, et al., "Investigation of Sub‐Bandgap Emission and Unexpected n‐Type Behavior in Undoped Polycrystalline CdSe <sub>x</sub> Te <sub>1‐x</sub>," Advanced Science 11, no. 29 (2024), https://doi.org/10.1002/advs.202309264
@article{osti_2369949,
author = {McGott, Deborah L. and Johnston, Steven W. and Jiang, Chun‐Sheng and Liu, Tuo and Kuciauskas, Darius and Glynn, Stephen and Reese, Matthew O.},
title = {Investigation of Sub‐Bandgap Emission and Unexpected n‐Type Behavior in Undoped Polycrystalline CdSe <sub>x</sub> Te <sub>1‐x</sub>},
annote = {Abstract Se alloying has enabled significantly higher carrier lifetimes and photocurrents in CdTe solar cells, but these benefits can be highly dependent on CdSe x Te 1‐x processing. This work evaluates the optoelectronic, chemical, and electronic properties of thick (3 µm) undoped CdSe x Te 1‐x of uniform composition and varied processing conditions (CdSe x Te 1‐x evaporation rate, CdCl 2 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 CdCl 2 ” (i.e., CdCl 2 anneal conditions used for group‐V‐doped devices). Low carrier lifetime is found for GrV‐optimized CdCl 2 , slow CdSe x Te 1‐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 ≈10 17 cm −3 . This behavior appears to originate during the CdCl 2 anneal, possibly from Se diffusion leading to anion vacancy (e.g., V Se , V Te ) and Cl Te generation. },
doi = {10.1002/advs.202309264},
url = {https://www.osti.gov/biblio/2369949},
journal = {Advanced Science},
issn = {ISSN 2198-3844},
number = {29},
volume = {11},
place = {Germany},
publisher = {Wiley Blackwell (John Wiley & Sons)},
year = {2024},
month = {06}}
2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC)https://doi.org/10.1109/PVSC.2018.8547402