Theoretical study impurities intermediate band material based on Sn heavily doped ZnO by first principles

We have performed a study on La heavily doped ZnO, based on the first principles. The calculated results show that with the increase of concentration of La, the lattice parameter is expanded. It is found that the top of valence band maximum is determined by the O-p states and the conduction band minimum is depended on the La-f and La-d states. The band gap of doping system is broadened as the increase of concentration of La, because the valence band moves towards lower energy more than the conduction band does. Furthermore, it is found that heavily doping of La with low concentration can enhance the conductivity of ZnO. The results are helpful to gain a systematic understanding of electrical properties of La-doped ZnO.

Download Full-text

Theoretical Study of the Electronic Structures of Na-Doped ZnO

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.665.124 ◽

2014 ◽

Vol 665 ◽

pp. 124-127 ◽

Cited By ~ 2

Author(s):

Qi Xin Wan ◽

Bi Lin Shao ◽

Zhi Hua Xiong ◽

Dong Mei Li ◽

Guo Dong Liu

Keyword(s):

Electronic Structure ◽

First Principles ◽

Electronic Structures ◽

Density Functional ◽

Formation Energy ◽

Theoretical Study ◽

The Other ◽

Functional Theory ◽

The Density Functional Theory ◽

Doped Zno

The first-principles with pseudopotentials method based on the density functional theory was applied to calculate the formation energy of impurities and the electronic structure of ZnO doped with Na. In Na-doped ZnO, NaOis the most unstable than the other cases. Simultaneously, NaZnis more stable than Naiaccording to that NaZnhave smaller formation energy. Furthermore, the electronic structure of Na-doped ZnO indicates that that NaZnbehaves as an acceptor, while Naibehaves as a donor.

Download Full-text

First Principles Calculations of Complex Intermediate Band Materials for Photovoltaic Devices

MRS Proceedings ◽

10.1557/proc-1211-r03-43 ◽

2009 ◽

Vol 1211 ◽

Author(s):

Perla Wahnón ◽

Irene Aguilera ◽

Pablo Palacios ◽

Kefren Sánchez

Keyword(s):

First Principles ◽

Active Element ◽

Point Of View ◽

Material Behavior ◽

First Principles Calculations ◽

Photovoltaic Devices ◽

Intermediate Band ◽

Photovoltaic Efficiency ◽

Band Material

AbstractAn ab initio study of several compounds candidates to behave as intermediate band materials is presented. The use of these materials as the active element in solar cells is a promising way to enhance the photovoltaic efficiency. Indeed from this point of view, most interesting compounds are those whose host semiconductor presents a band-gap close to the optimum value of 2 eV. Chalcogenide compounds substituted by light transition metals are solid candidates to this end. While they are being further characterized and experimentally synthesized, another approach is being examined. It consists of using Si as host semiconductor. Ti implantation at concentrations several orders of magnitude above equilibrium solubility has shown a probable intermediate band material behavior, the origin of the intermediate band being related to levels of interstitial Ti. Optoelectronic characterization of this material is completed. A novel possibility consists of combining chalcogen S implantation with boron. In this case preliminary results of electronic structure are shown.

Download Full-text