Gallium Selenide Nanoribbons on Silicon Substrates for Photodetection

Abstract

Layered semiconductor gallium selenide (GaSe) is considered a potential candidate for optoelectronic applications because of its direct band gap. Monocrystalline material is, however, a prerequisite to fully exploit these properties in devices, where one-dimensional nano-objects could be considered as a model system. As a consequence of their large surface-to-volume ratio, nano-objects such as nanoribbons are interesting for photodetection applications. Here, we report the vapor−liquid− solid growth of GaSe nanoribbons by MOCVD on 300 mm silicon substrates. A growth model is proposed on the basis of a comprehensive study of the impact of the growth parameters on the nanoribbon morphology. The nanoribbon microstructure is investigated by HR-STEM and Raman spectroscopy characterizations. HR-STEM and TEM cross-sectional observations coupled with EDX analyses reveal a monocrystalline nanoribbon core covered with a native gallium-oxide shell. Test devices are made by contacting individual nanoribbon. The current versus voltage (I−V) characteristic obtained over a range of temperature (−50 to 100 °C) in the dark and under white light illumination is fitted on the basis of a back-to-back Schottky diode model. A stable and repeatable dynamic photoresponse is measured from the GaSe nanoribbons, with an I ON /I OFF ratio of 17 at room temperature.

Enhanced photoresponse of PVP:GaSe nanocomposite thin film based photodetectors

“…Photo-responsivity characteristics were analyzed by encapsulating layered GaSe flakes in PVP, whose optoelectronic properties are quite strong but less studied due to production and oxidation-related problems [18][19][20][21][22][23]. Thanks to the method we used, photodetectors with enhanced light absorption performance were demonstrated by obtaining lowdimensional 2D GaSe structures from the bulk structure.…”

“…Also, the photocurrent measurement carried out by Lei et al shows that the indirect bandgap of monolayer GaSe is 3.3 eV, which makes it promising for the light detection at ultraviolet wavelengths [21]. Along with, GaSe combines the advantages of 2D structures for detection within the visible spectrum, with an easier route to integration with convensional silicon integrated circuits [22]. Moreover, the properties such as the absence of dangling bonds in GaSe and its thermal stability up to 600 °C make it draw attention in nanophotonic device applications [18].…”

Flexible Photodetectors with High Responsivity and Broad Spectral Response Employing Ternary SnxCd1–xS Micronanostructures

“…Photodetectors (PDs; ability to transform optical signals to electrical signals) have been paid considerable attention due to potential applications, including optical communications, binary switches, optical interconnects, environmental monitoring, flame sensing, high-resolution imaging techniques, missile plume detection, and optoelectronic memristors. − Due to their small size (similar to the Debye length) and large specific surface area, several types of one-dimensional (1-D) semiconductor micronanostructures have been utilized in PDs. ,− …”

A nanoflower-like GaSe/β-Ga2O3 based heterostructure for highly efficient self-powered broadband photodetectors

“…The maximum photocurrent occurs near 260 nm (band gap of Ga 2 O 3 ) in the device, and the second maximum value reaches 620 nm (GaSe band gap). 11,45 Since the photocurrent (I ph ) value of Ga 2 O 3 at 260 nm is higher than 620 nm, it is more sensitive than GaSe. In addition, the 361 nm peak indicates the near-band emission of GaN in the UVA region, and due to internal transitions to defect states, the film possesses a wide visible-range spectral band at 532 nm.…”