Device Simulation of Ag₂SrSnS₄ and Ag₂SrSnSe₄ Based Thin‐Film Solar Cells from Scratch

Abstract

The structural, optoelectronic and elastic properties of quaternary chalcogenide materials Ag 2 SrSn(S/Se) 4 in kesterite (Kes) and stannite (Sta) phases are studied using the HSE hybrid functional within the density functional theory. Ag 2 SrSnSe 4 in kesterite and stannite phases is found to have direct bandgap of 1.13 and 1.38 eV, respectively, along the high symmetry 𝚪 points. To analyze the electronic properties, PDOS for Ag 2 SrSn(S/Se) 4 in kesterite and stannite phases are studied and explained. To get more insights into the optical behavior of the materials the authors also investigate the dielectric function, refractive function, absorption spectrum, extinction coefficient, reflectivity, and optical conductivity. They also calculate the single-layer absorber efficiency of Ag 2 SrSn(S/Se) 4 in kesterite and stannite phases using the spectroscopic limited maximum efficiency (SLME) approach to predict their potential as an efficient absorber layer material in thin-film solar cells (TFSC). The SLME for Ag 2 SrSnSe 4 in kesterite and stannite phases is found to be 31.4% and 32.4%, respectively. Further, a complete solar cell device analysis with these materials as an absorber layer is carried out using the SCAPS-1D software. They found that devices with the kesterite and stannite structure of Ag 2 SrSnSe 4 have a predicted efficiency of 20.04% and 18.59%, respectively.

Improving the Performance of Lead‐Free FASnI3‐Based Perovskite Solar Cell with Nb2O5 as an Electron Transport Layer

“…In order to optimize the device entirely, we have also observed the capacitance-frequency (C-f) characteristics of the proposed PSC structure and the simulated C-f curves are illustrated in Figure 9. The characteristics of capacitance as a function of frequency are measured under zero-bias condition and at an operating temperature of 300 K. [65][66][67]69] The capacitance value is sufficiently low at the frequency below 10 7 Hz, as shown in Figure 9. However, the capacitance increases rapidly beyond 10 7 Hz, and the maximum capacitance is observed in the frequency ranged from 10 7 to 10 11 Hz.…”

“…The horizontal axis intercept typically corresponds to the V bi of organic semiconductor devices, and the slope of 1/C 2 (V) in the MS plot is interpreted as a density of engaged trapping centers. [64][65][66][67] 8a indicates that the capacitance rises gradually as the applied voltage increases. It is observed that there is a less significant change in the capacitance with the ETL donor density.…”

“…The V bi can be determined us- ing the MS equation, which links the capacitance per unit area and the doping density N A at the p-side in p-n junction. [65,66] The intercept of the inferred linear portion of the MS plot at the horizontal axis estimates the V bi of the PV device junction, [64][65][66][67] as shown in Figure 8b. Herein, the V bi of ≈0.67 eV at the optimized donor doping density of ETL is obtained for the proposed PSC structure.…”