Optically transparent ITO emitter contacts in the fabrication of InP/InGaAs HPT's

An optically transparent emitter InP/InGaAs heterojunction phototransistor (HPT) fabricated using Indium Tin Oxide (ITO) as the ohmic contact is presented for the first time; these devices show similar electrical characteristics to their opaque emitter counterparts and enhanced optical responsivities (5.4 A/W at 780 nm wavelength). Measured spectral response suggests responsivities of up to 30 A/W and 22 A/W at /spl lambda/=1310 nm and 1550 nm respectively.<
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