Theoretical Investigation of BGaAs/GaAs for Optoelectronic Device Applications
- PDF / 1,224,085 Bytes
- 7 Pages / 593.972 x 792 pts Page_size
- 14 Downloads / 194 Views
https://doi.org/10.1007/s11664-020-08389-z Ó 2020 The Minerals, Metals & Materials Society
Theoretical Investigation of BGaAs/GaAs for Optoelectronic Device Applications ARVIND SHARMA1,2 1.—Department of Basic and Applied Science, National Institute of Technology, Arunachal Pradesh, Yupia 791112, India. 2.—e-mail: [email protected]
Boron dopant incorporation into host GaAs material to form a novel BGaAs semiconductor has been studied using a 10-band kp model. This model allows us to calculate the electronic band structure along the crystallographic direction. So, from the obtained E–k relation, we calculate the carrier effective mass, intrinsic carrier concentration, and x = 0 (GaAs) are in good agreement with previously reported literature. The intrinsic carrier concentration variation is seen as monotonic with boron composition. On the other hand, the composition-dependent Debye temperature observed reduction along with symmetry directions, K by 1.23/%B, R by 2.33/%B, and D by 3.52/%B, which leads to the lower stability of crystalline BGaAs alloy. In addition, the interband absorption coefficient as a function of photon energy shows nonmonotonic dependence with fundamental absorption observed at 1.39 eV. Whereas, in the case of quantum well, the optical gain spectrum peak is blueshifted with the density of injected carriers. Hence, this study provides beneficial guidance in the interpretation of applications such as solar cells, optical modulators, multiple QWs. Key words: kp method, Debye temperature, optical gain, absorption coefficient
INTRODUCTION Highly mismatched alloys (HMA) have attracted great attention owing to their new potential application in bandgap engineering, and related optoelectronic integration.1,2 Specifically, BGaAs offer a new possibility in device applications such as square quantum wells,3 intermediate band solar cells,4 and photonic device applications.5 This novel ternary alloy is a combination of two binary alloys, GaAs and BAs, lattice-matched to 16%.3 In the previous research, GaAsN is classified as an HMA and has been the subject of attention because of its small size and high electronegativity. The HMA GaAsN has a variable direct bandgap, and the high absorption coefficient makes a promising material for multijunction solar cell applications. However, a
(Received May 27, 2020; accepted August 1, 2020)
lack of outcomes such as small incorporation of nitrogen onto GaAs drastically reduced the bandgap,6–8 and higher N concentrations have been challenging to achieve due to phase separation that occurs between wurtzite GaN and zincblende GaAs.9 Therefore, boron is used in place of nitrogen to overcome this problem due to the high solubility limit in GaAs.10 The electronegativity of boron is much smaller compared to nitrogen (as nitrides are highly ionic), leading to the strong covalent character of BGaAs alloys. Thus, alloying GaAs with boron is an alternative to nitrogen for bandgap engineering and strain compensation.10,11 Using tight-binding theory,12 a hybrid funct
Data Loading...
