Extremely high-performance visible light photodetector in the Sb2SeTe2 nanoflake

Abstract

The photocurrent was performed in the Sb2SeTe2 topological insulator at a wavelength of 532 nm. It exhibits extremely high performance that the responsivity and the photoconductive gain reach 2293 AW−1 and 5344 at 1 V. This high photoresponse is orders of magnitude higher than most reported values in topological insulators and two-dimensional transitional metal dichalcogenides. This finding suggests that the Sb2SeTe2 nanoflake has great potential for future optoelectronic device applications.

Robust broad spectral photodetection (UV-NIR) and ultra high responsivity investigated in nanosheets and nanowires of Bi2Te3 under harsh nano-milling conditions

“…Bi 2 Te 3 in combination with other material such as WS 2 and Si have been demonstrated the broad spectral photoresponsivity 21 , 38 . The nanoflakes of Sb 2 SeTe 2 and thin films of Sb 2 Te 3 have also shown high performing visible 39 and near infrared 24 photodetection recently. Huang et al .…”

Highly responsive photoconductance in a Sb2SeTe2 topological insulator nanosheet at room temperature

“…Several experimental works were performed on different topological insulators, which exhibited various kinds of characteristics that are expected to be able to be used in a wide range of applications. [10][11][12][13][14][15][16][17][18] It has come to our attention that most photocurrent experiments have mainly focused on the application of visible and near infrared light to topological insulators, graphene-topological insulator heterostructures and 2D TMDs. Work with ultraviolet light is relatively rare, and the reported photocurrent performance is low.…”

The Extremely Enhanced Photocurrent Response in Topological Insulator Nanosheets with High Conductance

“…Figure 2 a–c shows measured currents as a function of the light power intensity. Figure 2 d–f reveals that the measured current is proportional to the light power intensity [ 27 , 28 ]. The relation could be expressed as I on = β P α + I off , where the I on is the measured currents with light, I off is the measured currents without light, β is a constant related to the photocurrent response, P is the light power intensity, and α is a constant related to the light illumination condition between the devices and light.…”

“…1 , the linear voltage-current relation supports that nanosheets reveal a metallic behavior. The light-induced electron-hole pairs would travel to two electrode contacts due to the applied voltage bias [ 27 – 29 ]. Following Ohm’s law, the related photocurrent could be determined through the relation I ph = V G where V is the applied voltage bias between two electrodes.…”