Numerical and Experimental Study on the Device Geometry Dependence of Performance of Heterjunction Phototransistors
Jin-Lei Lu1,2, Chen Yue1,2, Xuan-Zhang Li1,2, Wen-Xin Wang1,2, Hai-Qiang Jia1,2,3, Hong Chen1,2,3, Lu Wang1,2**
1Key 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 2Center of Materials and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049 3Songshan Lake Materials Laboratory, Dongguan 523808
Abstract：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 ($A_{\rm e}/A_{\rm a}$) and the performance of HPTs, and to find the optimum value of $A_{\rm e}/A_{\rm a}$ for the geometric structure design, we develop an analytical model for the optical gain of HPTs. Moreover, five devices with different $A_{\rm e}/A_{\rm a}$ 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 $A_{\rm e}/A_{\rm a}$ 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 $A_{\rm e}/A_{\rm a}$ 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.
(Microcircuit quality, noise, performance, and failure analysis)
引用本文:
. [J]. 中国物理快报, 2019, 36(10): 108501-.
Jin-Lei Lu, Chen Yue, Xuan-Zhang Li, Wen-Xin Wang, Hai-Qiang Jia, Hong Chen, Lu Wang. Numerical and Experimental Study on the Device Geometry Dependence of Performance of Heterjunction Phototransistors. Chin. Phys. Lett., 2019, 36(10): 108501-.
2019, Vol. 36 
