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

Abstract

The low bandgap antimony selenide (Sb2Se3) and wide bandgap organic solar cell (OSC) can be considered suitable bottom and top subcells for use in tandem solar cells. Some properties of these complementary candidates are their non-toxicity and cost-affordability. In this current simulation study, a two-terminal organic/Sb2Se3 thin-film tandem is proposed and designed through TCAD device simulations. To validate the device simulator platform, two solar cells were selected for tandem design, and their experimental data were chosen for calibrating the models and parameters utilized in the simulations. The initial OSC has an active blend layer, whose optical bandgap is 1.72 eV, while the initial Sb2Se3 cell has a bandgap energy of 1.23 eV. The structures of the initial standalone top and bottom cells are ITO/PEDOT:PSS/DR3TSBDT:PC71BM/PFN/Al, and FTO/CdS/Sb2Se3/Spiro-OMeTAD/Au, while the recorded efficiencies of these individual cells are about 9.45% and 7.89%, respectively. The selected OSC employs polymer-based carrier transport layers, specifically PEDOT:PSS, an inherently conductive polymer, as an HTL, and PFN, a semiconducting polymer, as an ETL. The simulation is performed on the connected initial cells for two cases. The first case is for inverted (p-i-n)/(p-i-n) cells and the second is for the conventional (n-i-p)/(n-i-p) configuration. Both tandems are investigated in terms of the most important layer materials and parameters. After designing the current matching condition, the tandem PCEs are boosted to 21.52% and 19.14% for the inverted and conventional tandem cells, respectively. All TCAD device simulations are made by employing the Atlas device simulator given an illumination of AM1.5G (100 mW/cm2). This present study can offer design principles and valuable suggestions for eco-friendly solar cells made entirely of thin films, which can achieve flexibility for prospective use in wearable electronics.

TCAD-Based Design and Optimization of Flexible Organic/Si Tandem Solar Cells

“…The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/cryst14070584/s1, Figure S1: Absorption coefficients deduced from available experimental data for the bottom Si cell: (a) c-Si [54] and (b) a-Si layers [55]; Figure S2: Absorption spectrum of (a) PBDB-TCl:AITC absorber layer [34], (b) UV-vis absorption spectrum of PNDIT-F3N-Br layer [45], (c) Real, and (d) imaginary refractive index Refractive indices deduced from available experimental data for PEDOT:PSS layer [56]; Figure S3: (a) Illuminated J-V curves, and (b) EQE spectra of TSC and its cells, coupled using a tunnel junction; Figure S4: Efficiency over time for various tandem solar cell configurations from 2020 to 2024; Table S1: Definition of physical quantities used in Atlas device simulator; Table S2: Main parameters of various layers of organic solar cell [34,45,57]; Table S3: Defect parameters in OSC; Table S4: Main factors of various layers of thin Si cell [4,38,50,58]; Table S5: A state-of-the-art comparison between tandem cell metrics for a wide range of tandem systems [4,6,7,9,36,42,50,52,53,[59][60][61][62][63][64][65][66][67][68]…”

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

“…This endeavor underscores the suitability of Sb 2 Se 3 as the bottom sub-cell in tandem configurations, offering an imperative proof of concept. In [29], the authors investigated a tandem device composed of organic/Sb 2 Se 3 . After optimization and current matching, the inverted (p-i-n)/(p-i-n) tandem cell demonstrated a PCE of 21.52%.…”

“…Moreover, there exists a notable gap in the exploration of alternative materials, particularly those with potential cost and sustainability advantages. In comparison to Si and perovskite tandems, Sb 2 Se 3 -based tandems hold the promise of lower production costs and improved environmental sustainability, owing to the abundance and eco-friendliness of the constituent materials [29,37]. Additionally, compatibility with flexible substrates, position it as a competitive candidate for tandem configurations.…”

Exploring the potential of standalone and tandem solar cells with Sb2S3 and Sb2Se3 absorbers: a simulation study

“…Through optimization and current matching, the inverted tandem cell achieved an impressive power conversion efficiency (PCE) of 21.52%, while the conventional tandem cell achieved a PCE of 19.14%. The initial standalone top and bottom cells exhibited efficiencies of 9.45% and 7.89% respectively 29 . The crystal structures and characteristics of Sb 2 S 3 and Sb 2 Se 3 are, however, similar.…”