Construction of organic/GaN heterostructures for DUV-to-NIR broadband photodetection.

Herein, a broadband photodetector (BPD) is constructed with consistent and stable detection abilities for deep ultraviolet to near-infrared spectral range. The BPD integrates the GaN template with a hybrid organic semiconductor, PM6:Y6, via the spin-coating process, and is fabricated in the form of asymmetric metal-semiconductor-metal structure. Under an optimal voltage, the device shows consistent photoresponse within 254 to 850 nm, featuring high responsivity (10 to 60 A/W), photo-to-dark-current ratio over 103, and fast response time. These results show the potential of such organic/GaN heterojunctions as a simple and effective strategy to build BPDs for a reliable photo-sensing application in the future.

High Performance of Zero-Power-Consumption MOCVD-Grown ß-Ga2O3-Based Solar-Blind Photodetectors with Ultralow Dark Current and High-Temperature Functionalities.

In this article, we report on high-performance deep ultraviolet photodetectors (DUV PDs) fabricated on metal-organic chemical vapor deposition (MOCVD)-grown ß-Ga2O3 heteroepitaxy that exhibit stable operation up to 125 °C. The fabricated DUV PDs exhibit self-powered behavior with an ultralow dark current of 1.75 fA and a very high photo-to-dark-current ratio (PDCR) of the order of 105 at zero bias and >105 at higher biases of 5 and 10 V, which remains almost constant up to 125 °C. The high responsivity of 6.62 A/W is obtained at 10 V at room temperature (RT) under the weak illumination of 42.86 µW/cm2 of 260 nm wavelength. The detector shows very low noise equivalent power (NEP) of 5.74 × 10-14 and 1.03 × 10-16 W/Hz1/2 and ultrahigh detectivity of 5.51 × 1011 and 3.10 × 1014 Jones at 0 and 5 V, respectively, which shows its high detection sensitivity. The RT UV-visible (260:500 nm) rejection ratios of the order of 103 at zero bias and 105 at 5 V are obtained. These results demonstrate the potential of Ga2O3-based DUV PDs for solar-blind detection applications that require high-temperature robustness.

AlGaN-based Schottky barrier deep ultraviolet photodetector grown on Si substrate.

This letter reports the influence of material quality and device processing on the performance of AlGaN-based Schottky barrier deep ultraviolet photodetectors grown on Si substrates. The thermal annealing can significantly improve Schottky barrier height and wet chemical etching can effectively remove etching damage. Meanwhile, the decrease of threading dislocation density and the pit size, especially the later, can substantially suppress reverse leakage. As a result, the reverse leakage current density of the as-fabricated deep UV photodetector was reduced down to 3×10-8 A/cm2. Furthermore, the responsivity of the deep UV photodetectors was greatly improved by reducing the point defect concentration.