Features of Photoelectric Processes in CdS/CdTe Thin Film Heterosystems with Nanoscale Layers in Back Contacts

Authors A.L. Khrypunova , T.M. Shelest, A.I. Dobrozhan , A.V. Meriuts

National Technical University «Kharkіv Polytechnic Institute», 2, Kyrpychov St., 61002 Kharkiv, Ukraine

Е-mail dobr.abs@gmail.com
Issue Volume 13, Year 2021, Number 6
Dates Received 27 August 2021; revised manuscript received 04 December 2021; published online 20 December 2021
Citation A.L. Khrypunova, T.M. Shelest, A.I. Dobrozhan, A.V. Meriuts, J. Nano- Electron. Phys. 13 No 6, 06015 (2021)
DOI https://doi.org/10.21272/jnep.13(6).06015
PACS Number(s) 72.80.Ey, 84.60.Jt
Keywords Cadmium sulphide, Cadmium telluride (2) , Output parameters, Solar cell (51) , Light diode characteristics.

A comparative study of the influence of the solar radiation intensity level on the output parameters and light diode characteristics of solar cells (SCs) based on the CdS/CdTe heterosystem with different types of back contact has been carried out. It is shown that the studied SCs obtained by vacuum thermal evaporation method have the maximum efficiency under illumination conditions of 60 % AM1.5. The presence of a maximum is caused by a decrease in the fill factor of the light I-V characteristic due to a decrease in the shunt resistance, while the short-circuit current and open-circuit voltage increase with increasing illumination. In the case of solving the problem with a decrease in the shunt resistance, it can be expected that the tendency to an increase in the efficiency with increasing illumination level can be continued in the region of concentrated radiation. It is shown that not only the back contact material, but also the nature of the interphase interaction of the back contact with the base CdTe layer has a determinative influence on the illumination dependence of the series resistance of these SCs obtained by vaсuum thermal evaporation method. The observed nonmonotonic dependence of the diode saturation current density on the illumination level is associated with two competing physical mechanisms. One mechanism assumes the traditional increase in the diode saturation current due to an increase in the concentration of nonequilibrium charge carriers generated by light, and the other one determines a decrease in the diode saturation current due to the filling of traps, which leads to an increase in the charge carrier lifetime.

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