High performance monolithic GaAlAs/GaAs photodiode arrays for voltage-controlled semiconductor switches

Monolithic GaAlAs/GaAs photodiode arrays (PDA´s) have been developed as control elements for voltage-controlled switching applications. A p-type GaAs absorbing layer and an n-type GaAlAs window layer were grown by LPE on a semi-insulating GaAs substrate. Individual photodiodes were isolated and were series connected by an overlay metallization. A six cell PDA, having an active area of 1.28 mm², produces an open-circuit voltage of 5.3 V and a short-circuit current of 33 µA when subjected to a normally incident power flux of 50 mW/cm²at 865 nm. Such devices may be useful in a variety of voltage-controlled switching applications, opto-isolator circuits, and wherever low power, floating, voltage/bias sources are required.