TY - JOUR
T1 - Electronically Controlled Chemical Stability of Compound Semiconductor Surfaces
AU - Gao, Junning
AU - Lee, Yeonbae
AU - Yu, Kin Man
AU - Mao, Samuel S.
AU - Walukiewicz, Wladek
PY - 2019/9/4
Y1 - 2019/9/4
N2 - Effects of a humid environment on the degradation of semiconductors were studied to understand the role of the surface charge on material stability. Two distinctly different semiconductors with the Fermi level stabilization energy EFS located inside the conduction band (CdO) and valence band (SnTe) were selected, and effects of an exposure to 85 °C and 85% relative humidity conditions on their electrical properties were investigated. Undoped CdO films with bulk Fermi level EF below EFS and positively charged surface are very unstable. The stability greatly improves with doping when EF shifts above EFS, and the surface becomes negatively charged. This charge-controlled reactivity is further confirmed by the superior stability of undoped p-type SnTe with EF above EFS. These distinct reactivities are explained by the surface attracting either the reactive OH- or passivating H+ ions. The present results have important implications for understanding the interaction of semiconductor surfaces with water or, in general, ionic solutions.
AB - Effects of a humid environment on the degradation of semiconductors were studied to understand the role of the surface charge on material stability. Two distinctly different semiconductors with the Fermi level stabilization energy EFS located inside the conduction band (CdO) and valence band (SnTe) were selected, and effects of an exposure to 85 °C and 85% relative humidity conditions on their electrical properties were investigated. Undoped CdO films with bulk Fermi level EF below EFS and positively charged surface are very unstable. The stability greatly improves with doping when EF shifts above EFS, and the surface becomes negatively charged. This charge-controlled reactivity is further confirmed by the superior stability of undoped p-type SnTe with EF above EFS. These distinct reactivities are explained by the surface attracting either the reactive OH- or passivating H+ ions. The present results have important implications for understanding the interaction of semiconductor surfaces with water or, in general, ionic solutions.
KW - CdO
KW - Fermi stabilization energy
KW - moisture degradation
KW - semiconductor stability
KW - SnTe
KW - surface charge determined stability
KW - surface charge layer
UR - http://www.scopus.com/inward/record.url?scp=85071783096&partnerID=8YFLogxK
UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-85071783096&origin=recordpage
U2 - 10.1021/acsami.9b10739
DO - 10.1021/acsami.9b10739
M3 - RGC 21 - Publication in refereed journal
C2 - 31407878
SN - 1944-8252
VL - 11
SP - 32543
EP - 32551
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
IS - 35
ER -