Numerical Modeling to Improve the Efficiency of Cadmium Sulfide/Copper Indium Sulfide (CdS/CuInS2) Thin Film-based Solar Cells

Abstract

In this study, CIS-based devices were simulated and studied their performance by SCAPS (Solar Cell Capacitance Simulator) software. SCAPS is 1-dimensional graphic solar cell simulation software that estimates quantum efficiency, current-voltage characteristics, energy bands, and spectral response by solving Poisson's equations and continuity equations for electrons and holes. The solar cell structure was designed with CdS as an n-layer and CuInS2 as a p-layer for the first simulation and with ZnO as a window layer, CdS as a buffer layer, and with CuInS2 absorber layer for the next simulation. The CuInS2 layer thickness was changed from 0.5 to 2 µm, with other layer thicknesses kept constant, viz. 0.5 µm thickness for the CdS layer, which increased the solar cell efficiency from 5.6 to 8.47%. The optimized thickness of CuInS2 obtained was 2 µm. The thickness of ZnO varied from 0.15 to 1 µm, and the rest of the layer thicknesses were kept constant, viz. 2 µm for CuInS2, and 0.5 µm for CdS. An optimized 0.8 µm thickness of ZnO has been obtained with 12.74 % efficiency. The shallow uniform densities for the CuInS2 layer and ZnO layer were optimized to 1 X 10 18 (1/cm 3 ) and 1 X 10 15 (1/cm 3 ).

Numerical investigation on the role of ZnTe back surface layer in an efficient CuInS2 thin film solar cell

“…Its ionization energy is 6.9 eV. In contrast, p-CuInS 2 has the electron affinity and bandgap of 4.5 and 1.5 eV, in turn that provides an ionization energy of 6.0 eV [42]. This is why CdS creates a fine pn heterostrucutre with CuInS 2 .…”

Design and Simulation of a High‐Efficiency CuInS2 Thin‐Film Solar Cell with a Thin CIS Current Augmenter

“…The physical properties of each stratum listed in Table 1 have been gathered from a number of published researches. [1,19,22,27]…”

“…Overall, the PCE also improves insignificantly to 17.6 from 15.4% in the n-CdS/p-CuInS 2 /p þ -CuInSe 2 devices. Parameters n-CdS [1] p-CuInS 2 [27] p þ -CuInSe 2 [1,22] p þþ -MoS 2 [19] Thickness In addition, insertion of p þ -CIS layer within the n-CdS/ p-CuInS 2 /p þþ -MoS 2 solar device improves the J SC tremendously because of the high electric field in the p þ -CuInSe 2 /p þþ -MoS 2 interface, as shown in Figure 2c, which separates the electronhole pairs absorbed in the CIS layer before recombination. Thus, the CuInSe 2 layer acts as a current booster with MoS 2 BSF in the CuInS 2 PV cell.…”

Design and Simulation of an Environment-Friendly ZrS2/CuInS2 Thin Film Solar Cell Using SCAPS 1D Software

“…Silicon-based solar cells with a conversion efciency of less than 25% continue to dominate the solar cell market. Te main disadvantage of solar cells today is their low efciency and high manufacturing costs [2]. However, research is still needed to enhance existing materials or create new ones, which could lead to new opportunities for developing highly efective, low-cost, toxic-element-free devices.…”

“…CuInS 2 is the most suitable type of light-absorbing material. CuInS 2 is nontoxic [2], has a direct band gap (1.3-1.5 eV) [3], and has a high optical absorption coefcient (10 5 cm −1 ) [4] with long-term stability in solar applications [5]. Furthermore, toxic compounds such as Cd and Se are absent from CuInS 2 .…”