Schottky‐Contacted High‐Performance GaSb Nanowires Photodetectors Enabled by Lead‐Free All‐Inorganic Perovskites Decoration

Abstract

The surface Fermi level pinning effect promotes the formation of metal‐independent Ohmic contacts for the high‐speed GaSb nanowires (NWs) electronic devices, however, it limits next‐generation optoelectronic devices. In this work, lead‐free all‐inorganic perovskites with broad bandgaps and low work functions are adopted to decorate the surfaces of GaSb NWs, demonstrating the success in the construction of Schottky‐contacts by surface engineering. Benefiting from the expected Schottky barrier, the dark current is reduced to 2 pA, the Ilight/Idark ratio is improved to 103 and the response time is reduced by more than 15 times. Furthermore, a Schottky‐contacted parallel array GaSb NWs photodetector is also fabricated by the contact printing technology, showing a higher photocurrent and a low dark current of 15 pA, along with the good infrared photodetection ability for a concealed target. All results guide the construction of Schottky‐contacts by surface decorations for next‐generation high‐performance III–V NWs optoelectronics devices.

Flexible Omnidirectional Self-Powered Photodetectors Enabled by Solution-Processed Two-Dimensional Layered PbI2 Nanoplates

“…Moreover, the response time is another important parameter for the photodetectors. In general, the time of photocurrent increases from 10 to 90% peak value and vice versa is defined as the rise/decay time, respectively. − As shown in Figure e, the PbI 2 photodetectors have a common rise/decay time of 2/3 ms, which may be influenced by the large device size (1296 μm 2 ) and some tiny island-shaped nanocrystals in the surface of PbI 2 nanoplates that may act as recombination centers and trap states (SEM image, Figure S1a). To quantitatively assess the performance of PbI 2 photodetectors, the responsivity ( R = I ph / PA ) is calculated, where I ph , P , and A represent the photocurrent, power density of incident light, and the effective illuminated areas, respectively. ,, Recently, a more precise computational formula based on the noise equivalent power is used to calculate the detectivity. − Assuming that the shot noise from the dark current is the main limiting factor of the photodetector, the specific detectivity can be simplified as D * = RA 1/2 /(2 eI dark ) 1/2 , where e is the electron charge and I dark is the dark current .…”

“…To quantitatively assess the performance of PbI 2 photodetectors, the responsivity (R = I ph / PA) is calculated, where I ph , P, and A represent the photocurrent, power density of incident light, and the effective illuminated areas, respectively. 17,29,32 Recently, a more precise computational formula based on the noise equivalent power is used to calculate the detectivity. 33−36 Assuming that the shot noise from the dark current is the main limiting factor of the photodetector, the specific detectivity can be simplified as D* = RA 1/2 /(2eI dark ) 1/2 , where e is the electron charge and I dark is the dark current.…”

Nanowire-based synaptic devices for neuromorphic computing

“…Compared with 2D materials, NWs are more suitable for high integration and low power consumption synaptic devices. Nowadays, NWs have been integrated into diodes [30], field effect transistors (FETs) [31], memories [32], photodetectors [33], solar cells [34], and synaptic devices [19,23,35]. Based on the basic synaptic functionalities of NW-based synaptic devices, NWs can be constructed for neuromorphic computing.…”

CsCu2I3 thin films prepared by different deposition methods for ultraviolet photodetectors with imaging capability

“…based on Pb-based perovskite materials have developed rapidly and shown great potential for practical application due to their advantages of high light absorption, tunable band gap and low cost. [1][2][3][4][5][6][7][8][9] In particular, the incident photon-to-electron conversion efficiency of perovskite solar cells is close to that of the crystalline silicon cells. 10 However, the intrinsic toxicity issues of lead have hindered the environment-friendly application and commercialization of these devices.…”