Dirac semimetal Cd3As2 thin film grown by Molecular beam epitaxy on CdZnTe/Si capped by ZnTe
Yuan-Chih Hung1, Chun-Wei Kuo1, Jie-Ying Lee2, Sheng-Zong Chen2, Ji-Wei Ci1, Wei-Chen Lin2, Chien-Han Chen1, Chi-Te Liang2, Jyh-Shyang Wang3,4, Chiashain Chuang1,3*
1Department of Electronic Engineering, Chung Yuan Christian University, Taoyuan, Taiwan
2Department of Physics, National Taiwan University, Taipei, Taiwan
3Research Center for Semiconductor Materials and Advanced Optics, Chung Yuan Christian University, Taoyuan, Taiwan
4Department of Physics, Chung Yuan Christian University, Taoyuan, Taiwan
* Presenter:Chiashain Chuang, email:chiashain@cycu.edu.tw
ZnTe capping layer grown by molecular beam epitaxy (MBE) for the influence about transport properties of the Dirac semimetal Cd3As2 thin film on CdZnTe/Si(111) was studied. We show the van der Pauw (vdP) transport measurements of the MBE grown 10 nm ZnTe/100 nm Cd3As2/10 nm CdZnTe/Si(111) structure as shown in Fig. 1. The vdP mobility increased from 3500 cm2/Vs to 8500 cm2/Vs with decreasing temperature (T), which is much higher than that of thin film Cd3As2/CdZnTe/Si(111) without a capping layer the mobility (μvdP ~ 2000 cm2/Vs at room temperature). Such a direct MBE grown and reliable ZnTe capping layer could protect the Dirac semimetal Cd3As2 thin film from pollutants in air and can allow one to fabricate an oxide top gate device without decreasing the transport mobility. The inset of Fig. 1 shows the current and voltage (I-V) curve, exhibiting nearly the same linear ohmic behaviors at room temperature before and after a vacuum annealing at T = 375 K for around 1 minute. This result suggests the excellent semimetal transport behaviors with Rsq = 36 Ω and ideal Cd3As2 thin film without absorbing air molecules that changing the carrier densities so as to affect the quantum transport properties. Such important direct growth of MBE ZnTe capping layer on the Dirac semimetal Cd3As2 thin film device not only promotes the air-stable device, but also paves the way to integrate Cd3As2 with Si-based semiconductor technology and applications.


Keywords: Molecular beam epitaxy, Dirac semimetal, Cd3As2