Development of compact and fast modulators of infrared light has garnered strong research interests in recent years due to their potential applications in communication, imaging, and sensing. In this study, electric field induced fast modulation near-infrared light caused by phase change in VO2 thin films grown on GaN suspended membranes has been reported. It was observed that metal insulator transition caused by temperature change or application of electric field, using an interdigitated finger geometry, resulted in 7% and 14% reduction in transmitted light intensity at near-infrared wavelengths of 790 and 1550 nm, respectively. Near-infrared light modulation has been demonstrated with voltage pulse widths down to 300 µs at 25 V magnitude. Finite element simulations performed on the suspended membrane modulator indicate a combination of the Joule heating and electric field is responsible for the phase transition.

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The UV detection capabilities of III-nitride dual channel triangular microcantilevers, consisting of AlGaN/GaN two-dimensional electron gas channels with an intervening GaN layer, were investigated using 265, 315, and 375 nm illumination. High spectral responsivities, up to 2.3 × 10 4 A/W, were observed along with a very low dark current of a few pA, which resulted in a detectivity of 4.99 × 10 8 Jones. A high UV−visible rejection ratio of 10 4 was also measured between the wavelengths of 265 and 450 nm. A simple analysis of the photogenerated carriers indicates that the high responsivity arises out of a trap related high internal gain mechanism, while the low dark current and high photocurrent are caused by the suspended GaN interchannel layer and tapered channel geometry. The unique combination of high responsivity and detectivity, high gain, low dark currents, and high UV−visible rejection ratio can lead to the design of novel high-performance visible blind and solar blind UV photodetectors.

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