Dramatic enhancement in the gain of a GaAs/AlGaAs heterostructure bipolar transistor by surface chemical passivation

With a simple chemical treatment we have passivated nonradiative recombination centers at the periphery of a GaAs/AlGaAs heterostructure bipolar transistor, resulting in a 60-fold increase in the current gain of the device at low collector currents. This large enhancement in gain was achieved by spin coating thin films of Na2S9H2O onto the devices after their fabrication. We briefly discuss the passivation mechanism and the implications for other III-V optoelectronic devices.