Integrated AlGaN quadruple-band ultraviolet photodetectors

Monolithically integrated quadruple back-illuminated ultraviolet metal–semiconductor–metal photodetectors with four different spectral responsivity bands were demonstrated on each of two different Al x Ga 1- x N heterostructures. The average of the full-width at half-maximum (FWHM) of the quantum efficiency peaks was 18.15 nm for sample A, which incorporated five 1000 nm thick epitaxial layers. In comparison, the average FWHM for sample B was 9.98 nm, which incorporated nine 500 nm thick epitaxial layers.