Extraordinary Carrier Diffusion on CdTe Surfaces Uncovered by 4D Electron Microscopy

Ahmed El-Zohry, Basamat S. Shaheen, Victor M. Burlakov, Jun Yin, Mohamed N. Hedhili, Semen Shikin, Boon S. Ooi, Osman Bakr, Omar F. Mohammed

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


The lack of understanding and control over losses of charge carriers at the surfaces/interfaces of solar cell materials is the major factor limiting overall device conversion efficiency. This work describes a breakthrough in real-space visualization of charge-carrier dynamics at the atomic surface level of CdTe, a leading direct bandgap semiconductor in commercial thin-film solar cells. We present a fundamentally new understanding of charge-carrier diffusion and carrier trapping of CdTe single crystals using a four-dimensional scanning ultrafast electron microscope (4D-SUEM)—the only instrument of its kind currently in operation. We found that the diffusion of charge carriers at surfaces vary within extreme ranges, from extraordinary to virtually trapped when surface orientation was changed from (110) to (211). The work presented here is a milestone in addressing the device performance bottlenecks stemming from surfaces and a new avenue to create CdTe-based optoelectronic devices.
Original languageEnglish (US)
Pages (from-to)706-718
Number of pages13
Issue number3
StatePublished - Feb 1 2019

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: The research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST). We thank Dr. Daliang Zhang (KAUST Core Labs) for helping with the HR-TEM analysis and simulations.


Dive into the research topics of 'Extraordinary Carrier Diffusion on CdTe Surfaces Uncovered by 4D Electron Microscopy'. Together they form a unique fingerprint.

Cite this