In this era of environmental protection and performance, the development of organic photodetectors is booming. The hydrogel material is beginning to attract attention because of its characteristics such as plasticity and ecofriendliness. However, it is still a challenge to achieve a high-speed response in biophotodetectors. Herein, the development of an organic one-dimensional nanostructured photodetector is proposed through rotary-jet injection of gelatin fibers incorporated with silver nanoparticles (Ag NPs). The variation in the photoelectric properties of thin-film, fibrous structures with different diameters of approximately 40 μm and 400 nm has been investigated. In particular, the gelatin–Ag NPs fiber photoreceptor with a diameter of about 400 nm improved the light-to-dark current ratio by up to 28000% higher than the film structure, with rise and decay times of only 0.23 and 0.56 s. In addition, the nanostructure effectively boosts the photocurrent and suppresses the dark current because of its confining domains. The Ag NPs within the gelatin nanofibers produce localized surface plasmon resonance in the UV-illumination environment, enhancing the light absorption of the photosensitive layer, which contributes directly to the increase in the rate of excitons. The novel structure of the hybridized gelatin nanofibers incorporating silver nitrate has offered the promising potential for organic photodetectors.

The RF-sputtered ITO layers were used as the transparency contact layer of the MSM PDs. The plasma gas would alter the optical transmittance and the schottky barrier height between the ITO layer and InGaAsN absorption layer. Three kinds of plasma gases were studied including Ar, Ar/N 2 , and Ar/O 2 . The Schottky barrier heights were 0.510 eV, 0.572 eV, and 0.574 eV when using Ar, (Ar/N 2 ), and (Ar/O 2 ) as the plasma gas; besides, the optical transmittances were 92.56%, 93.12% and 96%, respectively. Although the ITO film sputtered in the Ar/O 2 ambient has highest transmittance and Schottky barrier height, the high resistivity limited the photocurrent of the photodetectors; it is almost three orders lower than the others. Consequently, using the Ar/N 2 as the plasma gas would be a suitable choice regarding the MSM photodetector application. The highest contrast ratio between photo-current and dark-current of the InGaAsN MSM photodetectors were 5, 25 and 12 (measured under 0.2V) using Ar, Ar/N2, and Ar/O2 as the plasma gases.

Natural materials are potential elements of environmentally friendly electronics for information storage. In this work, natural material-agar was used to fabricate the flexible resistive memory device. Agar is one of the most widely used biomaterials for tissue engineering, medicine, and other biotechnological applications. Agar is a suitable material for flexible electronics due to its good film formation, biocompatibility, low temperature solution-processibility, transparency, and flexibility. The flexible agar memory device exhibits the ON/OFF ratio of 103 under bending radius of 5 mm, good bending endurance, and a stable data retention time of over 104 s. Moreover, the agar could easily use leaf as substrate to make a fully biodegradable device. Due to the excellent flexibility of agar memory devices, agar is a candidate for becoming wearable and skin-compatible electronics.

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