Photocurrent Polarity Switching and Enhanced Photoresponse in Silver Nanoparticles Decorated a-GaN-Based Photodetector

Abstract

The photodetection properties of a-GaN nanorods-based photodetector and the effect of decorating silver nanoparticles are reported. For the pristine a-GaN detector, a surprising phenomenon of negative photoconductivity is observed, explained on the basis of defect states present in GaN nanorods. After the introduction of nanoparticles, the device exhibits reversal in the photocurrent polarity. The photoresponsivity reverses its sign from −0.12 A/W (bare a-GaN) to +6.75 A/W, with the introduction of nanoparticles (wavelength: 355 nm, 4.9 V bias). This current reversal and enhanced performance have been rationalized by considering passivation of surface defect states, resulting into significantly reduced dark current in the hybrid detector.

Brain-inspired computing: can 2D materials bridge the gap between biological and artificial neural networks?

“…These direct channels produce outstanding memristive behavior as the resistance states show a narrow distribution in one-dimensional structures. 56 Plasmonic and defect passivation: noble metal nanoparticles (NPs) have been utilized in the past due to their fascinating properties such as localized surface plasmon resonance (LSPR), [112][113][114] defect passivation, 115 etc. Metal NPs such as Au and Pt can be exploited as charge trapping elements in NVS devices due to their large electron affinity, higher chemical stability, easy synthesis procedure, etc.…”

New Charge Carrier Transport‐Assisting Paths in Ultra‐Long GaN Microwire UV Photodetector

“…A comparison of the photoconductive parameters of the GaN thin film and nanostructures-based UV PDs fabricated as MSM photoconductors is listed in Table 1. Figure 7b,c Nano-porous 325 0.329 @ 3 V bias 2.46 × 10 8 @ 3 V bias - [59] Nano-Obelisk 325 118 @ 14 V bias 3 × 10 10 @ 14 V bias 45000 @ 14 V bias [60] Thin film 325 0.28 @ 5 V bias 9.8 × 10 9 @ 5 V bias 107.04 @ 5 V bias [61] Porous 370 0.187 @ −3 V bias 4.34 × 10 12 @ −3 V bias 62.8 @ −3 V bias [62] Thin film 325 0.361 @ 10 V bias 2.3 × 10 10 @ 10 V bias 138 @ 10 V bias [63] Trigonal prism-shaped nanorod 325 0.259 @ 3 V bias 2.83 × 10 8 @ 3 V bias - [64] Nanorod 355 6.75 @ 4.9 V bias 2.75 × 10 10 @ 4.9 V bias - [65] Thin film 365 2.1 @ 1 V bias 1.3 × 10 9 @ 1 V bias - [66] Thin film 325 0.13 @ 5 V bias 9.79 × 10 8 @ 5 V bias 49.76 @ 5 V bias [67] Nanostructure 325 0.04 @ 3 V bias 5.3 × 10 10 @ 3 V bias - [68] Nanowall network 325 7.28 @ 3 V bias 2.7 × 10 9 @ 3 V bias - [69] Nanowire 325 14.752 @ −2 V bias 3.13 × 10 10 @ −2 V bias 5628.5 @ −2 V bias This work Microwire 325 28.365 @ −2 V bias 7.82 × 10 10 @ −2 V bias 10822 @ −2 V bias This work…”

Topological Bi2Se3/n-GaN Hybrid Structure for Enhanced and Self-Powered UV Photodetectors

“…Various efforts have been made to enhance the UV photodetection properties of MSM-based GaN UV PDs. Few researchers have reported the plasmonic enhancement of UV photodetection of GaN PDs using Au, Ag, and Pt nanoparticles because they induce the ‘local surface plasmon resonance (LSPR)’ effect which increases the light absorption efficiency, and hot carriers are injected into the semiconductor, followed by enhancement in the photocurrent. − Furthermore, it is well known that 2D materials have outstanding charge carrier transport and mobility, − and therefore, recently, in a few reports, different 2D materials have been used over WBG semiconductors for the fabrication of PDs. − Also, the 2D material/WBG semiconductor hybrid structure develops a built-in electric field that is capable of increasing the separation of photogenerated charge carriers and diminishing the recombination rate. As a result, the lifetime of photogenerated free charge carriers enhances, which improves the speed and response of the PD device.…”