Селенид сурьмы (Sb2Se3)

Description

Antimony selenide Sb2Se3 (antimony triselenide, antimony sesquiselenide) is a narrow-gap semiconductor with a one-dimensional crystal structure consisting of infinite chains of (Sb4Se6)n interconnected by relatively weak interchain interactions. This anisotropic structure provides directional charge transfer along the chains and determines the photoelectric properties of the material. In terms of its chemical family, the substance is related to antimony sulfide and telluride, but it is selenide that combines the band gap suitable for solar energy with the single-element, rather than binary, nature of the absorbing layer, which simplifies composition control during production.

Basic Attributes

• CAS No.: 1315-05-5
• Chemical formula: Sb2Se3

Properties (according to literature data)

• Semiconductor type: narrow bandgap, with tunable direct bandgap in the range of 1.2–1.9 eV
• Thermal stability: stable up to 500 °C, noticeable weight loss occurs in the ranges of 500-610 °C and 610-775 °C, which corresponds to decomposition processes
• Optical properties: high optical absorption coefficient, high Seebeck coefficient

Scope of application

A promising material for energy applications - photovoltaics, thermoelectrics and photodetectors - due to the availability of raw materials, low toxicity and suitable band gap. Thin-film solar cells based on Sb2Se3 have achieved conversion efficiency of up to 21.68% by optimizing the device architecture - a notable increase compared to 14.23% for a conventional cell design. A one-dimensional crystal structure with directional charge transfer along chains is considered an advantage for photovoltaics: defects at grain boundaries have less impact on device characteristics compared to three-dimensional semiconductors. In addition to solar cells, the material is being studied for thermoelectric cooling and phase-change memory due to its good photoconductive properties.

As an absorbing layer of a solar cell, Sb2Se3 is considered as a cheaper and environmentally friendly alternative to traditional thin-film technologies based on cadmium telluride and indium-gallium-selenium compounds: both elements of the material - antimony and selenium - are more widespread in the earth's crust than the rare metals of these technologies, and the toxicity of the compound is lower than that of cadmium-containing absorbers.

Appeal

As a compound of antimony and selenium, the material requires standard protective measures when working with powder - avoiding inhalation of dust and contact with skin and eyes, using exhaust ventilation when synthesizing and processing thin films. Thin Sb2Se3 films are produced by thermal evaporation, closed-space sublimation, chemical vapor deposition and hydrothermal synthesis - the choice of method determines the orientation of one-dimensional chains in the film and, accordingly, the final photoelectric efficiency of the device.