我們提出了新型的GaAs/In0.5Ga0.5P高速雷射功率轉換器(LPC)，不僅可以偵測高速的光訊號還有直流電功率的轉換。有兩個很嚴重的問題，會導致我們元件無法高速操作:其一是在光（830nm）激發所產生的電洞移動率很慢，另一為傳導帶偏移引起的電子阻斷效應，故我們分別利用漸變性參雜的P型GaAs作為吸收層和N型In0.5Ga0.5P為集極層來避免。此外，在順偏下會產生極大的接面電容，所以我們利用內切（undercut）In0.5Ga0.5P層來減少電容值，進而達到從0V～+0.8V皆可高速操作（~9 GHz），而在0.8V時是我們元件最高轉換效率的工作點(~15％)。We demonstrate novel GaAs/In0.5Ga0.5P high-speed laser power converters (LPCs), which not only can detect the envelope of incoming high-speed optical data but also can efficiently convert its optical dc component to dc electrical power. By utilizing the graded p-type GaAs and n-type In0.5Ga0.5P layers as photoabsorption (P) and collector (C) layers, respectively, the problem of slow-motion holes under 830-nm-optical-wavelength excitation and the conduction-band-offset- induced electron blocking effect between the P/C layers, which seriously limit the high-speed performance of LPC, can both be eliminated. Furthermore, by using the undercut mesa structure of the In0.5Ga0.5C layer to further reduce the large junction capacitance under forward operation, we can achieve invariable high-speed performance (~9 GHz) from zero to near turn-on voltage (+0.8 V), which corresponds to the operation point of our LPC with the maximum power conversion efficiency (~15%).
