1D/3D Alloying Induced Phase Transition in Light Absorbers for Highly Efficient Sb₂Se₃ Solar Cells

Abstract

A simple binary inorganic antimony selenide (Sb2Se3) compound is attractive as a promising light absorber for low‐cost and high‐efficiency photovoltaics. The external quantum efficiencies of Sb2Se3 solar cells are now approaching the optical limit values, which are comparable with the traditional well‐developed solar cells (such as Si, CuInGaSe2, CdTe, etc). However, the power conversion efficiency of the Sb2Se3 devices is constrained by the open‐circuit voltage (VOC) deficit, due to the intrinsic high resistivity and low element‐doping efficiency in such one‐dimensional (1D) crystals. Herein, a highly conductive, three‐dimensional (3D) crystal‐structure AgSbSe2 phase, formed by phase transition from low symmetry binary Sb2Se3, is introduced to control the doping density in the alloyed (Sb2Se3)x(AgSbSe2)1−x films utilizing configurational entropy. Guided by this alloying concept, 1D–3D (Sb2Se3)x(AgSbSe2)1−x alloy films with tunable doping densities are obtained. As a consequence, a noticeable improvement in VOC by >18% is observed in solar cells based on the (Sb2Se3)x(AgSbSe2)1−x alloy absorber layer, compared with the reference cell with a pure Sb2Se3 absorber, leading to a high conversion efficiency of 7.8%. This alloying model provides a universal approach to control the photoelectrical properties for high‐efficiency Sb2Se3‐based solar cells.

High Open‐Circuit Voltage in Full‐Inorganic Sb2S3 Solar Cell via Modified Zn‐Doped TiO2 Electron Transport Layer

“…The V bi of the Zn-TiO 2 -based device was 900 mV, which was 220 mV higher than pure TiO 2 -based device (680 mV). This huge margin of V bi can be attributed to an enhanced built-in electric field and improved interface quality, [35,36] leading to an immense increase in the V OC . Under short-circuit current conditions, the improved V bi also causes a higher energy band bending of the Sb 2 S 3 .…”

Boosting VOC of antimony chalcogenide solar cells: A review on interfaces and defects

“…Guo et al provided a strategy to obtain high-quality Sb 2 Se 3 films by alloying Sb 2 Se 3 with AgSbSe 3 (Figure 13G). [144] By incorporating Ag into the Sb 2 Se 3 , the carrier density of Sb 2 Se 3 could be adjusted from 10 16 to 10 17 cm −3 . This high carrier density allowed the V OC of alloy photovoltaic devices to reach an initial value of 475 mV, leading to a high PCE of 7.8%.…”

A Novel Thermochemical Metal Halide Treatment for High-Performance Sb2Se3 Photocathodes

“…Antimony (III) selenide (Sb 2 Se 3 ) has recently emerged as an eco-compatible and low-cost absorber material for various photo-assisted applications due to its advantageous optoelectronic properties ( E g ~1.2 eV, absorption coefficient > 10 5 cm −1 , high mobility) [ 7 , 17 , 18 , 19 , 20 , 21 ]. Besides, Sb 2 Se 3 is internally stable towards photocorrosion, and its elemental composition suggests less-complicated chemistry within the device processing compared to the multielement compounds such as CIGS and CZTS [ 7 , 10 , 22 ].…”

“…Despite significant efforts for improving the properties of typical absorber layers by various post-depositional treatments (PDTs) experienced for TFSCs [ 8 , 24 , 25 , 26 , 27 , 28 ], the procedures and their productivities of stable absorber/electrolyte interface are limited [ 29 ]. To date, most devices utilizing Sb 2 Se 3 layers exhibited parameters significantly below expectations [ 17 , 18 , 19 , 20 , 21 , 22 , 30 , 31 ]. The current record photocurrent density for compact Sb 2 Se 3 photoelectrodes has been predominantly attained by improvements in deposition methods in preference to realizing any suitable PDTs [ 22 ].…”