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.

MoS2 quantum dots (QDs)‐based white‐light‐emitting diodes (QD‐WLEDs) are designed, fabricated, and demonstrated. The highly luminescent, histidine‐doped MoS2 QDs synthesized by microwave induced fragmentation of 2D MoS2 nanoflakes possess a wide distribution of available electronic states as inferred from the pronounced excitation‐wavelength‐dependent emission properties. Notably, the histidine‐doped MoS2 QDs show a very strong emission intensity, which exceeds seven times of magnitude larger than that of pristine MoS2 QDs. The strongly enhanced emission is mainly attributed to nitrogen acceptor bound excitons and passivation of defects by histidine‐doping, which can enhance the radiative recombination drastically. The enabled electroluminescence (EL) spectra of the QD‐WLEDs with the main peak around 500 nm are found to be consistent with the photoluminescence spectra of the histidine‐doped MoS2 QDs. The enhanced intensity of EL spectra with the current increase shows the stability of histidine‐doped MoS2 based QD‐WLEDs. The typical EL spectrum of the novel QD‐WLEDs has a Commission Internationale de l'Eclairage chromaticity coordinate of (0.30, 0.36) exhibiting an intrinsic broadband white‐light emission. The unprecedented and low‐toxicity QD‐WLEDs based on a single light‐emitting material can serve as an excellent alternative for using transition metal dichalcogenides QDs as next generation optoelectronic devices.

A biologically inspired anthocyanin-graphene hybrid heterojunction has been designed and demonstrated to serve as a highly pH-value sensitive and self-powered photodetector. The photosensor shows a photo responsivity as high as...

Stretchable devices are an emerging class of future wearable technology, which have attracted a great attention, including all kinds of electronic and optoelectronic devices. Especially, owing to the excellent flexibility,...

Quantum dot light-emitting diodes (QLEDs) are an emerging class of optoelectronic devices with a wide range of applications. However, there still exist several drawbacks preventing their applications, including long-term stability, electron leakage, and large power consumption. To circumvent the difficulties, QLEDs based on a self-assembled hole transport layer (HTL) with reduced device complexity are proposed and demonstrated. The self-assembled HTL is prepared from poly[3-(6-carboxyhexyl)thiophene-2,5-diyl] (P3HT-COOH) solution in N,N-dimethylformamide (DMF) forming a well-ordered monolayer on an indium-tin-oxide (ITO) anode. The P3HT-COOH monolayer has a smaller HOMO band offset and a sufficiently large electron barrier with respect to the CdSe/ZnS quantum dot (QD) emission layer, and thus it is beneficial for hole injection into and electron leakage blocking from the QD layer. Interestingly, the QLEDs exhibit an excellent conversion efficiency (97%) in turning the injected electron–hole pairs into light emission. The performance of the resulting QLEDs possesses a low turn-on voltage of +1.2 V and a maximum external quantum efficiency of 25.19%, enabling low power consumption with high efficiency. Additionally, those QLEDs also exhibit excellent long-term stability without encapsulation with over 90% luminous intensity after 200 days and superior durability with over 70% luminous intensity after 2 h operation under the luminance of 1000 cd m–2. The outstanding device features of our proposed QLEDs, including low turn-on voltage, high efficiency, and long-term stability, can advance the development of QLEDs toward facile large-area mass production and cost-effectiveness.