Spectroscopic evidence for temperature-dependent convergence of light- and heavy-hole valence bands of PbQ (Q = Te, Se, S)

Journal Article · Fri Mar 10 00:00:00 EST 2017 · Europhysics Letters

DOI:https://doi.org/10.1209/0295-5075/117/27006· OSTI ID:1349520

Zhao, J. ^[1]; Malliakas, C. D. ^[2]; Wijayaratne, K. ^[1]; Karlapati, V. ^[1]; Appathurai, N. ^[1]; Chung, D. Y. ^[3]; Rosenkranz, S. ^[3]; Kanatzidis, M. G. ^[2]; Chatterjee, U. ^[1]

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1. Univ. of Virginia, Charlottesville, VA (United States)
2. Northwestern Univ., Evanston, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
3. Argonne National Lab. (ANL), Argonne, IL (United States)

Here, we have conducted a temperature- dependent angle-resolved photoemission spectroscopy (ARPES) study of the electronic structures of PbTe, PbSe and PbS. Our ARPES data provide direct evidence for the light-hole upper valence bands (UVBs) and hitherto undetected heavy-hole lower valence bands (LVBs) in these materials. An unusual temperature-dependent relative movement between these bands leads to a monotonic decrease in the energy separation between their maxima with increasing temperature, which is known as band convergence and has long been believed to be the driving factor behind extraordinary thermoelectric performances of these compounds at elevated temperatures.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; National Science Foundation (NSF)
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1349520
• Journal Information: Europhysics Letters, Vol. 117, Issue 2; ISSN 0295-5075
• Publisher: IOP Publishing
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY