High responsivity resonant-cavity-enhanced InGaAs/GaAs quantum-dot photodetector for wavelength of similar to 1 mu m at room temperature

The characteristics of a resonant cavity-enhanced InGaAs/GaAs quantum-dot n-i-n photodiode with only a bottom distributed Bragg reflector used as the cavity mirror, are reported. To suppress the dark current, an AlAs layer is inserted into the device structure as the blocking layer. It turns out that the structure still possesses the resonant coupling nature, and makes Rabi splitting discernible in the photoluminescence spectra. The measured responsivity spectrum of the photocurrent shows a peak at lambda = 1030 nm, and increases rapidly as the bias voltage increases. A peak responsivity of 0.75 A/W, or equivalently an external quantum efficiency of 90.3%, is obtained at V-bias = -1.4 V.

National Basic Research Program of China 2006CB932801 2007CB924903 2007CB924904 Chinese Academy of Sciences KJCX.YW.W09 This work was in part supported by the National Basic Research Program of China under No. 2006CB932801; 2007CB924903 and 2007CB924904, and also by the Special Research Programs of the Chinese Academy of Sciences and the Knowledge Innovation Program Project of Chinese Academy of Sciences under No. KJCX.YW.W09.