2D SiP₂/h-BN for a Gate-Controlled Phototransistor with Ultrahigh Sensitivity

Abstract

Two-dimensional (2D) materials are extremely attractive for the construction of highly sensitive photodetectors due to their unique electronic and optical properties. However, developing 2D photodetectors with ultrahigh sensitivity for extremely low-light-level detection is still a challenge owing to the limitation of high dark current and low detectivity. Herein, a gate-controlled phototransistor based on 2D SiP2/hexagonal boron nitride (h-BN) was rationally designed and demonstrated ultrahigh sensitivity for the first time. With a back-gate device geometry, the SiP2/h-BN phototransistor exhibits an ultrahigh detectivity of 3.4 × 1013 Jones, which is one of the highest values among 2D material-based photodetectors. In addition, the phototransistor also shows a gate tunable responsivity of ≤43.5 A/W at a gate voltage of 30 V due to the photogating effect. The ultrahigh sensitivity of the SiP2-based phototransistor is attributed to the extremely low dark current suppressed by the phototransistor configuration and the improved photocurrent by using h-BN as a substrate to reduce charge scattering. This work provides a facile strategy for improving the detectivity of photodetectors and validates the great potential of 2D SiP2 phototransistors for ultrasensitive optoelectronic applications.

Crude Polysaccharide Produces Silver Nanoparticles with Inherent Antioxidant and Antibacterial Activity

“…It indicates that biologically synthesized Ag‐NPs exhibited strong antioxidant potential and our results are following reported studies [26] . The observed antioxidant capacities may be due to residual polysaccharides coating the surface of the Ag‐NPs [27,28] . The experiments described above made it clear that the nanoparticles that were synthesized possessed promising antioxidant properties.…”

High-Detectivity and Broadband Photodetector Based on LiInP2Se6 Semiconductors

“…The performance of the photodetector might be improved by designing appropriate photodiode structures and optical configurations to maximize the capture and conversion of incident photons and optimizing the contact between LiInP 2 Se 6 and electrodes. Both R and D * decrease with the increase of the power density, which is also observed in MoS 2 , BP, and SiP 2 . , It might be owing to the decrease of the photoinduced carriers in the Auger process or the saturation of recombination/trap states …”

Multifunctional solar‐blind ultraviolet photodetectors based on p‐PCDTBT/n‐Ga2O3 heterojunction with high photoresponse

“…Note that the shot noise limit I shot is derived by I shot = (2qI dark ) 1/2 . 47 The noise current in the low-frequency region is dominated by the 1/f noise, while the noise current in the highfrequency region reaches the shot noise limit gradually. The noise current of the noise bandwidth of 1 Hz is as low as 0.21 pA Hz 1/2 in our work, which is assigned to be the main reason for the high photo-detectivity.…”

“…To further reveal the internal high photo‐detectivity to solar‐blind UV light of PCDTBT/a‐Ga 2 O 3 ‐based photodetector, the noise current versus different frequencies is investigated, as shown in Figure S8. Note that the shot noise limit I shot is derived by I shot = (2 qI dark ) 1/2 47 . The noise current in the low‐frequency region is dominated by the 1/ f noise, while the noise current in the high‐frequency region reaches the shot noise limit gradually.…”