Enhanced Broadband Responsivity of Ni-Doped Sb₂Se₃ Nanorod Photodetector

Abstract

Antimony selenide (Sb 2 Se 3 ) semiconductor with a narrow band gap is regarded as an ideal candidate for the next-generation broadband photodetectors. However, the photodetectors based on the binary Sb 2 Se 3 semiconductor suffer from low responsivity (R λ ) and external quantum efficiency due to the intrinsic low electrical conductivity. To address the issue, we introduce a low-valence Ni cation (Ni 2+ ) into the binary Sb 2 Se 3 ((Sb 1−x Ni x ) 2 Se 3 ) nanorods synthesized by a facile hot-injection process. With increasing Ni-doping concentration, the (Sb 1−x Ni x ) 2 Se 3 nanorods exhibit a significant increase of electrical conductivity from 4.983 × 10 −5 to 4.011 × 10 −4 Ω −1 m −1 . The photodetector based on (Sb 0.995 Ni 0.005 ) 2 Se 3 nanorod film exhibits an excellent responsivity of 18.9 mA/W under white light illumination of 45 mW/cm 2 at an applied bias voltage of 3 V, which is an approximately 19fold higher than that of the pristine Sb 2 Se 3 nanorod photodetector. Moreover, the density functional theory calculation has demonstrated that the Ni 2+ doped into Sb 2 Se 3 will preferentially occupy the Sb site and introduce a shallow energy level of acceptor, resulting in the enhancement of electrical conductivity, which is consistent with the experimental result. Therefore, the work proves the substitution of Sb site with a low-valence metal cation into Sb 2 Se 3 is an effective strategy to improve the performance of the Sb 2 Se 3 -based photodetector.

Advancing Graphitic Carbon Nitride-Based Photocatalysts toward Broadband Solar Energy Harvesting

“…Table summarizes some of the frequently used narrow-bandgap semiconductors and their bandgap values. Note that the chalcogenides (materials containing at least one chalcogen element, e.g., sulfur, selenium, or tellurium, as a substantial constituent, and at least one electropositive element), such as Ag 2 S, , Bi 2 S 3 , , MoS 2 , − WS 2 , − Sb 2 Se 3 , , In 2 Te 3 , account for a large proportion of narrow-bandgap semiconductors. They have also been directly utilized in photocatalysis to gain broadband photocatalytic activity.…”

Alternative Lone‐Pair ns2‐Cation‐Based Semiconductors beyond Lead Halide Perovskites for Optoelectronic Applications

“…In view of the existing effective recombination centers, [ 233 ] many studies have focused on strategies for inhibiting defects or incorporating impurities to elevate the Fermi level. [ 234–237 ] Following various approaches, including quasiepitaxy growth, surface sulfurization, and post‐treatment on Sb 2 S 3 films, the efficiency of Sb 2 S 3 ‐based solar cells can be improved by up to ≈7%. [ 238–240 ] Additionally, incorporating the effective impurities is also beneficial for increasing the carrier concentration.…”

“…Thus, by mapping a series of materials, including PbX (X = S, Se, Te), Sb 2 Te 3 , Bi 2 X 3 (X = Se, Te), and inorganic halide perovskites, into a 2D space with the ES and ET as two coordinates, they found MVB had well‐defined borders to covalent, and iono‐covalent regions, indicating its distinction. [ 229–307 ] Such a map demonstrated that the MVB mechanism approximately possessed one shared electron and moderate electron transfer between adjacent atoms. This predictive model can also give rise to the favorable characteristics in above materials, including large Born effective charge, high optical dielectric constants, strong optical interband transition, etc.…”

A High‐Performance Self‐Powered UV‐Visible‐Infrared Broadband Photodetector Based on a Solution‐Processed Bi2Se3/Se Nanorods Heterojunction

“…[ 14 ] 600–800% improvement of responsivity was realized in Se microtube photodetector by sputtering Au nanoparticles on surface of Se microtubes which had been reported by Hu et al. [ 15 ] In addition, strategies such as ion doping [ 16 ] and Schottky junction constructing [ 17 ] could also overcome the rapid recombination of photogenerated electron–hole pairs in photodetectors based on single material. Among these methods, heterojunction could effectively heighten the transportation and separation efficiency of charge carriers because a robust built‐in electric field would form at the heterojunction interface, leading to improved detection performance.…”