Carrier Transport Enhancement Mechanism in Highly Efficient Antimony Selenide Thin‐Film Solar Cell

Abstract

Exhibiting outstanding optoelectronic properties, antimony selenide (Sb 2 Se 3 ) has attracted considerable interest and has been developed as a light absorber layer for thin-film solar cells over the decade. However, current state-of-theart Sb 2 Se 3 devices suffer from unsatisfactory "cliff-like" band alignment and severe interface recombination loss, which deteriorates device performance. In this study, the heterojunction interface of an Sb 2 Se 3 solar cell is improved by introducing effective aluminum (Al 3+ ) cation into the CdS buffer layer. Then, the energy band alignment of Sb 2 Se 3 /CdS:Al heterojunction is modified from a "cliff-like" structure to a "spike-like" structure. Finally, heterojunction interface engineering suppresses recombination losses and strengthens carrier transport, resulting in a high efficiency of 8.41% for the substrate-structured Sb 2 Se 3 solar cell. This study proposes a facile strategy for interfacial treatment and elucidates the related carrier transport enhancement mechanism, paving a bright avenue to overcome the efficiency bottleneck of Sb 2 Se 3 thin-film solar cells.

Tellurium Doping Inducing Defect Passivation for Highly Effective Antimony Selenide Thin Film Solar Cell

“…When the bias voltage exceeds the kink point, which corresponds to the trap-filled limit voltage, the injected carrier fills the trap states in the TFL region ( V TFL ). [ 28 ] Then the defect density of the Sb 2 Se 3 thin film can be determined using the V TFL value according to the following equation [ 5 ]: where L represents the thickness of the Sb 2 Se 3 thin film, q represents the elementary charge, ε r represents the permittivity of the Sb 2 Se 3 and ε 0 represents the vacuum permittivity. The defect densities were calculated to 2.06 × 10 14 cm −3 and 1.86 × 10 14 cm −3 , respectively.…”

“…When the bias voltage exceeds the kink point, which corresponds to the trap-filled limit voltage, the injected carrier fills the trap states in the TFL region (V TFL ). [28] Then the defect density of the Sb 2 Se 3 thin film can be determined using the V TFL value according to the following equation [5]:…”

“…Antimony selenide (Sb 2 Se 3 ) has become a promising light-harvesting material, thanks to the advantages of high earth abundance, low toxicity, superior photoelectric properties, and a high light absorption coefficient [ 1 , 2 , 3 , 4 , 5 ]. Sb 2 Se 3 as a binary compound has high stability and fixed stoichiometry.…”

Improved Carrier Lifetimes of CdSe Thin Film via Te Doping for Photovoltaic Application

“…Previous experiments have shown that the average carrier lifetime of the CdSe thin film is less than 200 ps, which is the most important factor greatly limiting the efficiency. As the DFT calculation mentioned above, the Te element serves as a good passivation for the CdSe thin films that can reduce the hole capture coefficient and the recombination rate, hence it is theoretically possible to increase the carrier lifetime . Time-resolved photoluminescence (TRPL) mapping was used to study the photogenerated carrier dynamics in thin films.…”

Multi‐Phase Sputtered TiO2‐Induced Current–Voltage Distortion in Sb2Se3Solar Cells

“…[ 1–5 ] In addition to this material's favorable combination of properties; boasting a nearly ideal 1.18 eV band gap, [ 6 ] high absorption coefficient, [ 7–9 ] low toxicity and high stability, [ 10–12 ] Sb 2 Se 3 has further demonstrated a high degree of versatility. It is capable of being deposited in both substrate [ 13–17 ] and superstrate [ 18–26 ] geometries and with a wide variety of deposition techniques; from low temperature solution‐based methods, [ 21,24–26 ] to high temperature physical vapor deposition approaches. [ 13–15,18–20,22,23 ] This has led to a rapid improvement in performance with a record power conversion efficiency ( PCE ) of 10.6% for the pure selenide composite [ 25 ] and 10.7% for the Sb 2 (S,Se) 3 alloy.…”