High-temperature excitons and enhanced electroabsorption in InGaAs/InAlAs multiple quantum wells

Sharp heavy-hole and light-hole excitons are clearly observed for the first time in InGaAs/InAlAs multiple-quantum-well (MQW) structures at temperatures ranging from -190°C to 70°C. The halfwidth of the heavy-hole exciton line is as narrow as 6.2 meV at room temperature. InGaAs/InAlAs MQWs are prepared in a PIN doped configuration by molecular beam epitaxy. An enhanced electroabsorption effect is also clearly observed in long-wavelength-region MQWs.