High-Performance Visible Light Photodetector Based on BiSeI Single Crystal

Abstract

The continuing demand for new optoelectronic devices drives researchers to seek new materials suitable for photodetector applications. Recently, ternary compound semiconductors have entered researchers’ field of vision, among which chalcohalides have attracted special interest because of their rich properties and unique crystal structure consisting of atom chains and inter-chain van der Waals gaps. We have synthesized high-quality BiSeI single crystals with [110]-plane orientation and fabricated a photodetector. The optoelectronic measurements show a pronounced photocurrent signal with outstanding technical parameters, namely high responsivity (3.2 A/W), specific detectivity (7 × 1010 Jones) and external quantum efficiency (622%) for λ = 635 nm, V ds = 0.1 V and P opt = 0.23 mW/cm2. The high performance of BiSeI photodetector and its layer structure make it a promising candidate for low-dimensional optoelectronic applications.

Enhanced optoelectronic performance and photogating effect in quasi-one-dimensional BiSeI wires

“…Its crystal structure is composed of double chains [(BiSeI) ∞ ]2 along the 𝑏 axis, where Bi and Se atoms are connected by covalent bonds and I ions have ionic bonds with a covalent binding bridge. 23 BiSeI is an indirect bandgap semiconductor with a bandgap of ~ 1.32 eV, which has been confirmed by the first-principles calculations 24 and reflectivity measurement. 25 In addition, BiSeI has been studied as a promising photovoltaic material, 26 manifesting the application potential in optoelectronics.…”

“…Indeed, the photodetector constructed on the bulk crystal shows an obvious photoresponse under visible light. 24 Considering that the reduced size and dimensionality of quasi-1D materials usually cause a crossover in properties, the reduced size of BiSeI crystal is expected to induce a significant change in optoelectronic performance. Moreover, a nonstoichiometric effect and iodine vacancies are observed in the bulk crystals.…”

“…High-quality single crystals of BiSeI were grown by the physical vapor transport (PVT) method. 24 Single crystal X-ray diffraction (XRD) measurement was performed on a Rigaku Miniflex X-ray diffractometer using Cu Kα radiation. Raman spectra were collected on a Horiba JobinYvon T6400 spectrometer with a 532 nm laser.…”

“…The previous study has shown that BiSeI has a significant response to the entire visible-light spectrum, with the largest response to green light. 24 Figures 2(d)-2(f) show the Ids-Vds curves obtained in the dark and under a 515 nm laser for D1, D2 and D3, respectively. The data obtained with the lasers of other wavelengths are presented in the supplementary material.…”

Broadband photoresponse arising from photo-bolometric effect in quasi-one-dimensional Ta2Ni3Se8

“…To further evaluate the optoelectronic performance, some key parameters are calculated, including responsivity (R = can be obtained. These parameters are significant, even in comparison with other outstanding photodetectors fabricated on ternary compounds [29][30][31][32][33][34] or quasi-1D wires [29,30,35,36]. Considering the broadband photoresponse, the advantage of Ta2Ni3Se8 photodetector is more prominent.…”