Perovskite Chalcogenides with Optimal Bandgap and Desired Optical Absorption for Photovoltaic Devices

Abstract

Solar cells with organic‐inorganic lead halide perovskites have achieved great success and their power conversion efficiency (PCE) has reached to 22.1%. To address the toxicology of lead element and some stability issues associated with the organic‐inorganic lead halide perovskites, inorganic lead‐free perovskites have gained more attentions from the photovoltaic research community. Herein, a series of chalcogenide perovskites are proposed as optical absorber materials for thin‐film solar cells. SrSnSe3 and SrSnS3 are predicted to be direct bandgap semiconductors with the bandgap value being within the optimal range of 0.9–1.6 eV. Both SrSnSe3 and SrSnS3 not only exhibit good optical absorption properties and carrier mobility, but also possess flexible bandgaps that can be continuously tuned within the grange of 0.9–1.6 eV via the element‐mixing strategy, thereby render both perovskites as promising candidates for photovoltaic applications.

Perovskite Solar Absorbers: Materials by Design

“…Ju et al investigated a series of Sn/Ge‐based chalcogenide perovskites ABX 3 , where A = Ca, Sr, or Ba, B = Sn, Ge, or Te, and X = S, Se, or O with distorted perovskite structures based on DFT calculations . Eight compounds showed bandgaps within the optimal range.…”

2D Ca3Sn2S7 Chalcogenide Perovskite: A Graphene‐Like Semiconductor with Direct Bandgap 0.5 eV and Ultrahigh Carrier Mobility 6.7 × 104 cm2 V−1 s−1

“…Here, we pay particular attention to chalcogenide perovskites because they were little known before but have now gained huge traction among researchers . Recently, Sun et al predicted 18 chalcogenide compounds and found that CaTiS 3 , BaZrS 3 , CaZrSe 3 , and CaHfSe 3 are promising solar cell materials due to their suitable bandgaps (0.95–1.75 eV).…”

“…e) Computed optical absorption of 2D 1L–3L Ca 3 Sn 2 S 7 , in which the underestimated PBE bandgap has been modified based on GGA‐1/2 calculations. For comparison, the optical absorption in important photovoltaic materials Si and MAPbI 3 are also shown. Inset: The orbital characteristics of VBM and CBM are given, where the dipole‐allowed intra‐atomic transitions (the solid arrows) and the SSn covalent bond transition (the dashed arrow) are indicated.…”

“…Moreover, the splitting of cationic valence state and the mixture of anions in the perovskite structure provide more possibilities for component engineering, which greatly modulates the electronic structure (bandgap and electronic dispersion) of the designed perovskite material.Here, we pay particular attention to chalcogenide perovskites because they were little known before but have now gained huge traction among researchers. [14][15][16][17] Recently, Sun et al [14] predicted 18 chalcogenide compounds and found that CaTiS 3 , BaZrS 3 , CaZrSe 3 , and CaHfSe 3 are promising solar cell materials due to their suitable bandgaps (0.95-1.75 eV). Ju et al [15] report that SrSnSe 3 and SrSnS 3 are energetic photovoltaic materials with optimal direct bandgap (0.9-1.6 eV), high absorption coefficient (10 5 cm −1 ), and small carrier effective mass (0.12-0.65 m 0 ).…”

“…[14][15][16][17] Recently, Sun et al [14] predicted 18 chalcogenide compounds and found that CaTiS 3 , BaZrS 3 , CaZrSe 3 , and CaHfSe 3 are promising solar cell materials due to their suitable bandgaps (0.95-1.75 eV). Ju et al [15] report that SrSnSe 3 and SrSnS 3 are energetic photovoltaic materials with optimal direct bandgap (0.9-1.6 eV), high absorption coefficient (10 5 cm −1 ), and small carrier effective mass (0.12-0.65 m 0 ). Moreover, BaZrS 3 and CaZrS 3 have also been synthesized by using the high-temperature sulfurization of their oxide counterparts by Perera et al [16] Quite recently, a 2D RP-type chalcogenide perovskite, Ba 3 Zr 2 S 7 , with an optimal bandgap (1.28 eV) for single-junction photovoltaic device and Graphene, a star 2D material, has attracted much attention because of its unique properties including linear electronic dispersion, massless carriers, and ultrahigh carrier mobility (10 4 -10 5 cm 2 V −1 s −1 ).…”