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In this work, nitrogen‐doped zinc‐tin‐oxygen (ZnSnO:N) optoelectronic synaptic thin film transistors (TFTs) with superior visible light response are fabricated. Nitrogen doping narrows the bandgap of ZnSnO, which in turn broadens the absorption spectrum. Additionally, the reduction of non‐radiative centers in the channel layer prolongs the lifetime of the photogenerated electrons, resulting in enhancements to the photo response throughout the visible region. Optoelectronic synaptic devices based on ZnSnO:N TFTs can accurately replicate synaptic behaviors, including short‐term plasticity (STP) and long‐term plasticity (LTP). Furthermore, the ZnSnO:N optoelectronic synaptic TFT‐based array has the potential to improve image contrast. The ZnSnO:N TFT exhibits a considerable improvement in both visible light photosensitivity and synaptic plasticity. [ABSTRACT FROM AUTHOR]

Optoelectronic synapse, well coupling the optical and electrical signals in one device, is an important building block in neuromorphic hardware library. Herein, optoelectronic synaptic devices are demonstrated based on a unique amorphous oxide semiconductor (InGaCdO [IGCO]) that can be spiked by broadband light signals from ultraviolet to near‐infrared region, approaching the wavelength of 1000 nm. These optically stimulated synaptic devices are based on the conventional bottom‐gate thin‐film transistor (TFT) configuration, providing the beneficial process/structural compatibility with the flat‐panel display industry. The IGCO TFTs, showing an ultrahigh field‐effect mobility up to 106 cm2 V−1 s−1, can well simulate a series of basic synaptic functionalities via changing the pulse intensity, number, and frequency. The device plasticity originates from the dynamic ionization and neutralization of oxygen vacancy‐related defects. Also, the mechanism underlying this dynamic process is discussed in detail, verifying that oxygen vacancy can turn to its ionized state by directly absorbing a photon having enough energy or with the aid of holes. The relatively higher carrier mobility, smaller bandgap, and larger activation energy of oxygen vacancy for the IGCO together facilitate the achievement of broadband optoelectronic synaptic devices. [ABSTRACT FROM AUTHOR]

Concerning the revolutionary future of electronic devices, high-performance solution-processable semiconductors have earned increasing academic and industrial research interests. In this paper, we synthesize In-Ga-Cd-O semiconductor thin films via a solution method. Transparent amorphous/nanocrystalline oxide thin films with small surface roughness have been grown by controlling the relative ratio of Cd-content. The present thin-film transistor with an optimized Cd-ratio exhibits a saturation field-effect mobility up to 10 cm² V-1 s-1, an on/off current ratio of ≈1.3×109, and a threshold voltage shift of ≈2.6 V under -5 V gate bias of 10 000 s, which are superior or comparable to those reported values of solution-processed conventional In-Ga-Zn-O counterparts. Our results indicate that the proposed In-Ga-Cd-O semiconductor would endow a promising transparent amorphous/nanocrystalline active material for electronic devices. [ABSTRACT FROM AUTHOR]

In this article, we report the growth of zinc‐tin nitride (ZnSnN2) thin films as a potential absorber for photovoltaic applications by fabricating a heterojunction of n‐ZnSnN2/p‐SnO. The performance of the heterojunction has been monitored through selective deposition of top electrode with different materials (Ni/Au or Al). The electron‐transfer process from the ZnSnN2 layer to the cathode is facilitated by selecting metal electrode with relatively low work function, which also boosts up the electron injection or/and extraction. The diode exhibits a good J–V response in the dark with a rectification ratio of 3 × 103 at 1.0 V and an ideality factor of 4.2 in particular with Al as the top electrode. Under illumination, the heterostructure solar cell demonstrates a power conversion efficiency of ≈0.37% with an open circuit voltage of 0.25 V and a short circuit current density of 4.16 mA cm−2. The prime strategies, on how to improve solar cell efficiency concerning band offsets and band alignment engineering are also discussed. [ABSTRACT FROM AUTHOR]