Schottky barrier photodetectors based on AlGaN

We report solar-blind ${\mathrm{Al}}_x{\mathrm{Ga}}_{\text{1−x}}\mathrm{N}$ photovoltaic detectors with cutoff wavelengths as short as 290 nm. Mesa geometry devices of different active areas are fabricated and characterized for spectral responsitivity, speed, and noise performance. The responsivity of the devices near the cutoff wavelength is 0.07 A/W. The detector noise is found to be $\text{1/f}$ limited, with a noise equivalent power of ${\text{6.6×10}}^{\text{−9}}\hspace{0.17em}\mathrm{W}$ over the total response bandwidth of 100 kHz.