High absorption (>90%) quantum-well infrared photodetectors

The intrinsic short carrier lifetime $\text{(∼5\hspace{0.05em}}\mathrm{ps})$ makes the quantum-well infrared photodetector (QWIP) well suited for high speed and high frequency applications. In such cases, since lasers are commonly used, a high dark current can be tolerated. The most important parameter is then the absorption efficiency. For system simplicity and potential wide use, room temperature operation is desirable. Using GaAs/AlGaAs QWIPs, high absorption $\text{(∼100\%)}$ and up to room temperature operation are achieved in devices having high doping densities and 100 quantum wells.