Electron and hole multiplication characteristics have been measured on a series of Al 0.52 In 0.48 P p + -i-n + and n + -i-p + homojunction diodes with nominal avalanche region thicknesses ranging from 0.22 to 1.03 µm. From these, the electron and hole impact ionization coefficients are deduced over an electric-field range from 530 to 990 kV/cm. The results suggest that the electron ionization coefficient is larger than the hole ionization coefficient, particularly at lower electric fields. Extremely low dark currents were obtained, and there was no evidence of any tunneling dark current even at electric fields of approximately 1.0 MV/cm. From these ionization coefficients, we deduce that the breakdown voltage in Al 0.52 In 0.48 P is almost 2.5× greater than that of GaAs and 4.5× lower than that of GaN.

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Abstract-The absorption properties of Al 0.52 In 0.48 P have been investigated near the fundamental absorption edge by measuring the photocurrent as a function of wavelength in a series of PIN and NIP diodes. Modelling of the photocurrent in these structures enables the absorption coefficients to be determined accurately over a wide dynamic range, which allows the direct and indirect band-gap to be determined.

The temperature dependence of avalanche multiplication and breakdown voltage in Al0.52In0.48P, lattice-matched to GaAs, has been measured on a series of p+-i-n+ and n+-i-p+ diodes with nominal avalanche region thicknesses ranging from 0.068 to 1.0 μm from 77.8 to 298 K. From this, impact ionization coefficients as a function of temperature have been determined. For a given avalanche region thickness, Al0.52In0.48P exhibits temperature coefficient of breakdown voltage smaller than those of Ga0.52In0.48P and Al0.6Ga0.4As by approximately 1.6× and 2.0×, respectively. Our analysis shows that the alloy disorder potential and alloy composition ratio may be responsible for the large variation in temperature coefficient of breakdown voltages observed in a range of III–V ternary semiconductors.