Numerical Simulations on CZTSSe-Based Solar Cells with GaSe as an Alternative Buffer Layer Using SCAPS-1D

Abstract

In recent years, because of non-toxic characteristic, relatively high efficiency, and adjustable band gap, the research on thin film solar cells using Cu2ZnSn (SxSe1-x)4 (CZTSSe) as the absorber layer material has been in full swing. But its large band gap width makes it easy to form an excessive potential barrier with other materials, leading to the raise of the recombination probability of carriers. Therefore, it is necessary to select a suitable buffer layer to optimize such solar cells. Compared with the common buffer material CdS, GaSe crystal has a high damage threshold, strong anisotropy, and nonlinear optical properties. In this paper, GaSe was selected as the buffer layer of the solar cell with CZTSSe as the absorber layer. At the same time, traditional holes transport layer was removed to save its complex manufacturing process. The addition of GaSe also adjusted the energy band arrangement of the battery, which alleviated the strong potential barrier between the absorber layer and the window layer to improve the carrier transport effectively. The effects of the impurity ratio, thickness, temperature, and defect density on the device performance were also discussed in detail, which provides a reference for experimental preparation and industrial application.

Designing if CZTSSe Based PbS Thin Film Solar Cell for Improved Conversion Efficiency

“…The performance of a solar cell depends mainly on the absorption of incident photons, the generation and separation of electrically opposite carriers, and the transport of light-generated carriers to the contacts (Xuefei Wu et al 2022). These processes depend on the electrical and optical properties of the different materials used in the solar cell structure (Aryan Kannaujiya et al 2022).…”

“…These processes depend on the electrical and optical properties of the different materials used in the solar cell structure (Aryan Kannaujiya et al 2022). For thin film solar cells, the absorber layer is an indispensable structure for the photoelectric reaction, as well as the two electrodes for storing electrons and holes (Xuefei Wu et al 2022). All other structures are designed to increase the conversion efficiency of carrier transport, i.e., the rate and amount of carrier transport There are two important steps in the working process of a solar cell, one is the absorption of photons and conversion of electrons, and the other is the transport of carriers (Aryan Kannaujiya et al 2022).…”

“…The BSF layer creates a rearward thrust on the backside of a highly doped solar cell, which results in the deflection of minority carriers towards the front depletion region (Sudheendra Prabh et al 2021). Lead sulfide (PbS) is a promising BSF layer (Xuefei Wu et al 2022). It has higher electron affinity and better absorption coefficient than materials such as SnS, Al2O3, and MoSe2 BSF, low cost, and abundant reserves (Shivani et al 2019).…”