Investigation of Polymer/Si Thin Film Tandem Solar Cell Using TCAD Numerical Simulation

Abstract

The current study introduces a two-terminal (2T) thin-film tandem solar cell (TSC) comprised of a polymer-based top sub cell and a thin crystalline silicon (c-Si) bottom sub cell. The photoactive layer of the top sub cell is a blend of PDTBTBz-2F as a polymer donor and PC71BM as a fullerene acceptor. Initially, a calibration of the two sub cells is carried out against experimental studies, providing a power conversion efficiency (PCE) of 9.88% for the top sub cell and 14.26% for the bottom sub cell. Upon incorporating both sub cells in a polymer/Si TSC, the resulting cell shows a PCE of 20.45% and a short circuit current density (Jsc) of 13.40 mA/cm2. Then, we optimize the tandem performance by controlling the valence band offset (VBO) of the polymer top cell. Furthermore, we investigate the impact of varying the top absorber defect density and the thicknesses of both absorber layers in an attempt to obtain the maximum obtainable PCE. After optimizing the tandem cell and at the designed current matching condition, the Jsc and PCE of the tandem cell are improved to 16.43 mA/cm2 and 28.41%, respectively. Based on this TCAD simulation study, a tandem configuration established from an all thin-film model may be feasible for wearable electronics applications. All simulations utilize the Silvaco Atlas package where the cells are subjected to standard one Sun (AM1.5G, 1000 W/m2) spectrum illumination.

Mixed cations tin-germanium perovskite: A promising approach for enhanced solar cell applications

“…On the other hand, cliff band will increase and facilitate faster recombination at the interface [ 62 , 64 ]. For thin-film solar cells, a flat-band or spikes band is usually preferred as the photogenerated holes go towards the back electrode instead of the n-type layer, which means that the valence band discontinuity between an absorber layer and an n-type layer is less significant [ 64 , 65 ].…”

Proposal and Numerical Analysis of Organic/Sb2Se3 All-Thin-Film Tandem Solar Cell

“…The chosen cells are based on organic, polymer, antimony chalcogenide (Sb 2 X 3 , where X = S, Se, or S x Se 1−x ) or Si subcells. It is evident from the literature that theoretical analysis of tandem devices based on Si has demonstrated high PCE due to the high current capability of the Si bottom cell [56,57]. However, an important finding is that increasing the Si thickness is associated with an increase in PCE which poses a challenge for producing flexible tandems, in addition to the higher cost of Si compared to thin-film technology.…”

Optimization of all-polymer/Sb2Se3 tandem solar cells for enhanced efficiency: a comprehensive TCAD modeling approach

“…Silvaco atlas simulation methodology TCAD simulation plays a crucial role in advancing semiconductor device development by enabling researchers to model and analyze device behavior and performance. Silvaco TCAD stands out as a powerful tool for simulating tandem solar cells, offering a comprehensive range of features tailored to the complex requirements of multi-junction PV devices [38][39][40]. With Silvaco TCAD, one can model the optical and electrical characteristics of each sub-cell, considering factors like bandgap variation, and absorption coefficients.…”