Surface-Barrier CdTe Diodes for Photovoltaics

Authors Tetiana Mazur , Myroslav Mazur , Marian Halushchak

Ivano-Frankivsk National Technical University of Oil and Gas, 15, Karpatska Str., 76019 Ivano-Frankivsk, Ukraine

Issue Volume 15, Year 2023, Number 2
Dates Received 01 February 2023; revised manuscript received 19 April 2023; published online 27 April 2023
Citation Tetiana Mazur, Myroslav Mazur, Marian Halushchak, J. Nano- Electron. Phys. 15 No 2, 02006 (2023)
PACS Number(s) 61.43.Gt, 68.37.Ps, 78.30.Fs, 78.55. – m
Keywords Surface barrier diode, CdTe (15) , Short circuit current (2) , Open-circuit voltage, Quantum efficiency (3) .

In this paper, a comparative analysis of the use of semiconductor solar cells based on single-crystal, polycrystalline and amorphous silicon (Si), as well as cadmium telluride (CdTe) in the energy sector is carried out. It is shown that the advantages of thin-film technology and CdTe itself as a direct-gap semiconductor open the prospect of large-scale production of competitive CdTe solar modules (batteries). The technology of manufacturing substrates, applying indium ohmic contact to the plates, exposing some of the substrates to a number of additional treatments in an aqueous suspension of alkali metals, in particular Li – CdTe:Li and conducting research on them, as well as on chemically etched substrates that have not undergone any additional processing and conventionally designated CdTe. The possibilities of using devices based on single-crystal CdTe, which are called surface barrier diodes (SBDs), are being studied for converters. Technological advances that lead to changes in the physicochemical properties of single-crystal surfaces of n-CdTe substrates (their main optical, electrical, and photoelectric parameters, as well as the characteristics of metal-semiconductor contacts based on single-crystal cadmium telluride) are being discussed. Analyzing the properties of the research objects it should be noted that surface modification not only affects the potential barrier height but also significantly changes the course of electric and photoelectric processes, while the surface morphology of CdTe:Li substrates remains similar to unmodified ones, although the SBDs based on them are noticeably higher. It was also found that the rate of surface recombination of SBDs based on substrates with a surface nanostructure is two and one orders of magnitude lower than in structures based on basic substrates and alkali metal salts treated in suspension, respectively. The modification of substrates leads to an increase in the efficiency of solar cells (SCs), and the highest photoconversion efficiency is observed for SBDs based on substrates with a surface nanostructure and reaches 9 % at 300 K under AM2 illumination. The methods of using the technologies proposed in this work for the creation of surface-barrier photocells based on thin CdTe films are considered.

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