Low-temperature-dependent property in an avalanche photodiode based on GaN/AlN periodically-stacked structure

Jiyuan Zheng,Qian Li,Jiadong Yu,Jian Wang,Yi Luo,Xiao Meng,Hongtao Li,Bing Xiong,Mo Li,Zhibiao Hao,Di Yang,Changzheng Sun,Yanjun Han,Lai Wang

doi:10.1038/srep35978

Jiyuan Zheng, Qian Li + Show 12 more

Open Access

https://doi.org/10.1038/srep35978

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Abstract

In ultra-high sensitive APDs, a vibrate of temperature might bring a fatal decline of the multiplication performance. Conventional method to realize a temperature-stable APD focuses on the optimization of device structure, which has limited effects. While in this paper, a solution by reducing the carrier scattering rate based on an GaN/AlN periodically-stacked structure (PSS) APD is brought out to improve temperature stability essentially. Transport property is systematically investigated. Compared with conventional GaN homojunction (HJ) APDs, electron suffers much less phonon scatterings before it achieves ionization threshold energy and more electrons occupy high energy states in PSS APD. The temperature dependence of ionization coefficient and energy distribution is greatly reduced. As a result, temperature stability on gain is significantly improved when the ionization happens with high efficiency. The change of gain for GaN (10 nm)/AlN (10 nm) PSS APD from 300 K to 310 K is about 20% lower than that for HJ APD. Additionally, thicker period length is found favorable to ionization coefficient ratio but a bit harmful to temperature stability, while increasing the proportion of AlN at each period in a specific range is found favorable to both ionization coefficient ratio and temperature stability.

Highlights

In ultra-high sensitive avalanche photodiode (APD), a vibrate of temperature might bring a fatal decline of the multiplication performance
We focus on exploiting the high temperature stability potentiality for GaN/AlN periodically-stacked structure (PSS) APD
It can be seen from the figure that the St of both PSS APD and HJ APD decrease with electric field

Summary

Introduction

In ultra-high sensitive APDs, a vibrate of temperature might bring a fatal decline of the multiplication performance. Compared with conventional GaN homojunction (HJ) APDs, electron suffers much less phonon scatterings before it achieves ionization threshold energy and more electrons occupy high energy states in PSS APD. In conventional HJ APDs based on commonly used materials such as Si, GaAs, InP, GaN, SiC, energy of electron or hole gathered from electric field is greatly thermalized due to phonon scattering[2,3,4,5,6]. In order to achieve high gain, APD should work under extremely high bias, where both electron and hole could trigger ionization to form positive feedback ionization chain. In this case, the APD performance is highly sensitive to temperature. APDs have to be mounted on a temperature maintained thermoelectric cooler to avoid temperature change[9], which reduces the integration level of system

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Conclusion