Enhanced breakdown voltages in strained InGaAs/GaAs structures

The breakdown voltage (VBD) in a semiconductor is usually proportional to its band-gap (Eg) through the dependence of the impact ionization process on the threshold voltage (Eth). It has recently been suggested that strain can cause Eth to increase even when Eg decreases, raising the possibility of narrow band-gap materials with large VBD. By growing a range of strained InGaAs/GaAs multiple quantum well (MQW) pin diode structures and measuring VBD, we show that the presence of strained InGaAs increases VBD confirming that it has a larger Eth than GaAs.