Speaker: Dr. Xi Zhu, NTU
Copper Zinc Tin Sulphide (CZTS) semiconductor is a material with the optimal single junction band gap and has high absorption efficiency. Compared with other better-studied solar cell materials such as CuInSe2, CdTe and CIGS, all the constituent elements in CZTS are more nontoxic and earth abundant, thus make it gain a lot attention to be a high efficiency, low cost and environmental friendly solar cell. Though CZTS is a promising material for future solar energy scavenging, their electronic properties that determine the energy conversion efficiencies are not well understood, such as the responsible intrinsic defects for p-type conductivity, and the region of stable phases and defect state and grain boundary physics are also important issue in studying CZTS. On the other hand, to using CZTS in high efficiency solar cell devices, it is necessary to investigate properties into its surface level. We investigate into the crystal structure of CZTS and its electronic properties of both bulk and surface using Density Functional Theory with Generalized gradient approximation. The surface character including the phase stability is well studied to provide more understanding for the surface effect for the CZTS materials.
About the speaker:
Dr Zhu Xi received his BS from University of Science and Technological University in 2002 and Ph.D from Nanyang Technoligical University in Singapore in 2011. After that he keeps as a research fellow at Nanyang Technological University.
His research interests are focused on studying the properties of solar cell materials by simulation methods, especially the interface charge transfer.