RESONANT-TUNNELING TRIANGULAR-BARRIER OPTOELECTRONIC SWITCH BY GAS-SOURCE MOLECULAR-BEAM EPITAXY

We report a novel optical bistable device, resonant-tunneling triangul ar-barrier optoelectronic switch (R-TOPS), which consists of a double- barrier resonant-tunneling diode (DB-RTD) and a triangular-barrier pho totransistor (TBP), grown by gas source molecular beam epitaxy (GSMBE) . First, we studied the potential of the GSMBE to grow a DB-RTD and a TBP. The DB-RTD with In0.53Ga0.47As(well)/AIAs(barrier) exhibited clea r negative differential resistance (NDR). Interfaces between In0.53Ga0 .47As and AIAs in the DB-RTD were of good quality without dislocations in spite of the strained AIAs layers. On the other hand, the TBP with n(+)-i-delta p(+)-i-n(+) structure composed of In0.53Ga0.47As/In(0.52 )Al(0.48)AS layers was fabricated on InP, which was the first demonstr ation of a TBP at 1 mu m wavelength range operation to our knowledge. On these basis, we fabricated the R-TOPS devices. Sharp NDR with clear bistability was successfully observed, and its characteristics were d ependent on optical input power. Bistability was observed in the relat ion between input-light power and output-current. By connecting the de vice to a laser diode, clear optical bistability and sharp optical NDR property with high contrast and at low input-light power were also de monstrated. We found that both the TBP and the DB-RTD worked well in t he R-TOPS grown by GSMBE.