TY - JOUR
T1 - Grain-Boundary-Enhanced Carrier Collection in CdTe Solar Cells
AU - Li, Chen
AU - Wu, Yelong
AU - Poplawsky, Jonathan
AU - Pennycook, Timothy J.
AU - Paudel, Naba
AU - Yin, Wanjian
AU - Haigh, Sarah J.
AU - Oxley, Mark P.
AU - Lupini, Andrew R.
AU - Al-Jassim, Mowafak
AU - Pennycook, Stephen J.
AU - Yan, Yanfa
PY - 2014/4/16
Y1 - 2014/4/16
N2 - When CdTe solar cells are doped with Cl, the grain boundaries no longer act as recombination centers but actively contribute to carrier collection efficiency. The physical origin of this remarkable effect has been determined through a combination of aberration-corrected scanning transmission electron microscopy, electron energy loss spectroscopy, and first-principles theory. Cl substitutes for a large proportion of the Te atoms within a few unit cells of the grain boundaries. Density functional calculations reveal the mechanism, and further indicate the grain boundaries are inverted to n type, establishing local p-n junctions which assist electron-hole pair separation. The mechanism is electrostatic, and hence independent of the geometry of the boundary, thereby explaining the universally high collection efficiency of Cl-doped CdTe solar cells.
AB - When CdTe solar cells are doped with Cl, the grain boundaries no longer act as recombination centers but actively contribute to carrier collection efficiency. The physical origin of this remarkable effect has been determined through a combination of aberration-corrected scanning transmission electron microscopy, electron energy loss spectroscopy, and first-principles theory. Cl substitutes for a large proportion of the Te atoms within a few unit cells of the grain boundaries. Density functional calculations reveal the mechanism, and further indicate the grain boundaries are inverted to n type, establishing local p-n junctions which assist electron-hole pair separation. The mechanism is electrostatic, and hence independent of the geometry of the boundary, thereby explaining the universally high collection efficiency of Cl-doped CdTe solar cells.
UR - http://www.scopus.com/inward/record.url?scp=84898996346&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.112.156103
DO - 10.1103/PhysRevLett.112.156103
M3 - Article
AN - SCOPUS:84898996346
SN - 0031-9007
VL - 112
JO - Physical Review Letters
JF - Physical Review Letters
IS - 15
M1 - Article No. 156103
ER -