摘要
Heterojunction phototransistors(HPTs)with scaling emitters have a higher optical gain compared to HPTs with normal emitters.However,to quantitatively describe the relationship between the emitter-absorber area ratio(Ae/Aa)and the performance of HPTs,and to find the optimum value of Ae/Aa for the geometric structure design,we develop an analytical model for the optical gain of HPTs.Moreover,five devices with different Ae/Aa are fabricated to verify the numerical analysis result.As is expected,the measurement result is in good agreement with the analysis model,both of them confirmed that devices with a smaller Ae/Aa exhibit higher optical gain.The device with area ratio of 0.0625 has the highest optical gain,which is two orders of magnitude larger than that of the device with area ratio of 1 at 3 V.However,the dark current of the device with the area ratio of 0.0625 is forty times higher than that of the device with the area ratio of 1.By calculating the signal-to-noise ratios(SNRs)of the devices,the optimal value of Ae/Aa can be obtained to be 0.16.The device with the area ratio of 0.16 has the maximum SNR.This result can be used for future design principles for high performance HPTs.
Heterojunction phototransistors(HPTs)with scaling emitters have a higher optical gain compared to HPTs with normal emitters.However,to quantitativel.y describe the relationship between the emitter-absorber area ratio(A_e/A_a)and the performance of HPTs,and to find the optimum value of A_e/A_a for the geometric structure design,we develop an analytical model for the optical gain of HPTs.Moreover,five devices with different A_e/A_a are fabricated to verify the numerical analysis result.As is expected,the measurement result is in good agreement with the analysis model,both of them confirmed that devices with a smaller A_e/A_a exhibit higher optical gain.The device with area ratio of 0.0625 has the highest optical gain,which is two orders of magnitude larger than that of the device with area ratio of 1 at 3 V.However,the dark current of the device with the area ratio of 0.0625 is forty times higher than that of the device with the area ratio of 1.By calculating the signal-to-noise ratios(SNRs) of the devices,the optimal value of Ae/Aa can be obtained to be 0.16.The device with the area ratio of0.16 has the maximum SNR.This result can be used for future design principles for high performance HPTs.
作者
鲁金蕾
岳琛
李炫璋
王文新
贾海强
陈弘
王禄
Jin-Lei Lu;Chen Yue;Xuan-Zhang Li;Wen-Xin Wang;Hai-Qiang Jia;Hong Chen;Lu Wang(Key Laboratory for Renewable Energy,Beijing Key Laboratory for New Energy Materials and Devices,Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190;Center of Materials and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049;Songshan Lake Materials Laboratory,Dongguan 523808)
基金
Supported by the National Natural Science Foundation of China under Grant Nos 11574362,61210014,11374340 and 11474205
the Innovative Clean-Energy Research and Application Program of Beijing Municipal Science and Technology Commission under Grant No Z151100003515001
the National Key Technology R&D Program of China under Grant No 2016YFB0400302
