Improvement in nonlinear characteristics of zero bias GaAsSb-based backward diodes

A high curvature coefficient (γ) of 49.4 V^-1 was achieved at zero bias using p-GaAsSb/i-InAlAs/n-InGaAs backward diodes that were lattice-matched to an InP substrate. γ indicates a higher value than that of ideal Schottky diodes (39.6 V^-1). Backward diodes with such a high y are applicable in mixers. The doping concentration in the p-GaAsSb layer was optimized to obtain an ideal energy band structure for a backward diode. The impedance-matched voltage sensitivity (β_v,opt) at 94 GHz was estimated to be 6,069 V/W using a diode of 3.0 μm diameter.