Dual‐Mode Conversion of Photodetector and Neuromorphic Vision Sensor via Bias Voltage Regulation on a Single Device

Abstract

Simultaneous implementation of photodetector and neuromorphic vision sensor (NVS) on a single device faces a great challenge, due to the inherent speed discrepancy in their photoresponse characteristics. In this work, a trench‐bridged GaN/Ga2O3/GaN back‐to‐back double heterojunction array device is fabricated to enable the advanced functionalities of both devices on a single device. Interestingly, the device shows fast photoresponse and persistent photoconductivity behavior at low and high voltages, respectively, through the modulation of oxygen vacancy ionization and de‐ionization processes in Ga2O3. Consequently, the role of the optoelectronic device can be altered between the photodetector and NVS by simply adjusting the magnitude of bias voltage. As a photodetector, the device is able to realize fast optical imaging and optical communication functions. On the other hand, the device exhibits outstanding image sensing, image memory, and neuromorphic visual pre‐processing as an NVS. The utilization of NVS for image pre‐processing leads to a noticeable enhancement in both recognition accuracy and efficiency. The results presented in this work not only offer a new avenue to obtain complex functionality on a single optoelectronic device but also provide opportunities to implement advanced robotic vision systems and neuromorphic computing.

An Organic Optoelectronic Synapse with Multilevel Memory Enabled by Gate Modulation

“…This could be suggestive of a transition from short-term plasticity to longterm plasticity. 5,54 The PPF and PTP indexes, derived using eqs 5 and 6, exhibited a consistent decrease as the pulse interval was extended from 1 to 20 s (Figure 3d). This decremental trend aligns with a double-exponential function model as follows, mirroring behavior patterns observed in biological synapses 54…”

“…The observation that τ 1 is lower than τ 2 by more than an order of magnitude aligns well with the decay dynamics observed within biological synapses. 54 The transition from STP to LTP can be attained by modulating the number of pulses (Figure 3e and 3f) and the light intensity (Figure 3g and 3h). As shown in Figure 3e and 3f, both the transient current and the memory current markedly increase as a function of the pulse number.…”

Surface Passivation to Enhance the Interfacial Pyro-Phototronic Effect for Self-Powered Photodetection Based on Perovskite Single Crystals

“…30 The charge carriers tend to transmit directly across the leaky Schottky barrier instead of the external circuit. The highest values for responsivity (R) and detectivity (D*) are achieved at 0.3 A/W and 1 × 10 10 Jones, respectively, under the lowest intensity of 0.13 μW/cm 2 . In this study, the R and D* were calculated and visually represented as a function of power…”

“…Photodetectors (PDs) are optoelectronic devices that serve a crucial function in diverse domains, such as optical communication, optical guidance technology, and environmental monitoring, by converting light into electrical signals. − Self-powered PDs are highly sought after for sensing in extreme conditions such as environmental sensing, chemical sensing, and biosensing. This is due to their advantageous features of wireless operation, maintenance-free functionality, and absence of external power requirements.…”

Dipole Field-Driven Organic–Inorganic Heterojunction for Highly Sensitive Ultraviolet Photodetector

“…The preparation process is illustrated in Figure . ZnO thin films prepared by the sol–gel method are used as seeds and electron-transport layers, ZnO NRs are hydrothermally grown on the ZnO seed layer as an n-type UV light response layer, and P:P with high conductivity, transparency, low sheet resistance, and simple low-temperature solution processability is selected as a hole transport layer and electron blocking layer to cover the surface of the ZnO NRs. − Meanwhile, the transition-metal oxide MoO 3 with high work function (WF) is used as the anode buffer layer, which can effectively suppress the Fermi level pinning. , A picture of the MZP composite film is displayed in Figure S1. Due to the low concentrations of 0.01 M MgZnO NRs and 0.03 M MgZnO NRs, a good contact could not be formed with P:P, resulting in subpar film quality, as shown in Figure S1a,b.…”