A facile and one-pot approach to the preparation of gold (Au) and copper (Cu) bimetallic nanoclusters (NCs) is unveiled. AuCu NCs reveal features of orange photoluminescence (PL), reversible pH-dependent PL properties, and efficient catalytic activity for degradation of methylene blue (MB).
Recently, mixed-dimensional p-n heterojunctions have shown desirable optoelectronic functionalities. However, relatively little is known about the influence of interfacial traps on electron transport under external bias. Here, we explore the prominent dual optoelectronic characteristics of n-MoS2/p-GaN heterostructures, including photodetection and persistent photocurrent (PPC). The photoresponsivity was found to achieve as high as ∼105 A W−1 for 532 nm laser illumination under reverse bias. Additionally, the device exhibits the long-lasting PPC with a decay time constant (460 s) under forward bias. The results indicate that the hybrid heterojunctions not only function as high performance photodetectors under reverse bias but also have potential to use the unique property of PPC for other optoelectronic applications under forward bias alternatively.
In this paper, we numerically study an enhancement of breakdown voltage in AlGaN/GaN high-electron-mobility transistors (HEMTs) by using the AlGaN/GaN/AlGaN quantum-well (QW) electron-blocking layer (EBL) structure. This concept is based on the superior confinement of two-dimensional electron gases (2-DEGs) provided by the QW EBL, resulting in a significant improvement of breakdown voltage and a remarkable suppression of spilling electrons. The electron mobility of 2-DEG is hence enhanced as well. The dependence of thickness and composition of QW EBL on the device breakdown is also evaluated and discussed.
We report the photoluminescence studies of pristine and diethylenetriamine-doped (DETA-doped) WS2 quantum dots (QDs) synthesized by pulsed laser ablation. The DETA-doped WS2 QDs revealed a notable improvement of the luminescence quantum yield from 0.1% to 15.2% in comparison to pristine WS2 QDs. On the basis of the photoluminescence (PL) under different excitation wavelengths and the emission-energy dependence of PL dynamics, we suggest that the excitation-wavelength-dependent (excitation-wavelength-independent) PL for pristine (DETA-doped) WS2 QDs is attributed to the recombination of carriers from the localized (delocalized) states.