Schematic of the CIGS solar cell model.
A horizontal cut of the band diagram taken from the junction for a positive GB potential of . CBM is the conduction-band minimum and VBM is the valence-band maximum.
(Color) The electron current density when the GB potential is (a) , (b) , and (c) . The arrows indicate the direction of electron flow and not the magnitude. The legend corresponds to all three graphs.
(Color) The electron current density when the bulk electron and hole mobilities are 100 and and the GB electron and hole mobilities are 0.1 and , respectively. The GB region extends from . The arrows indicate the direction of electron flow and not the magnitude.
The efficiency , , , and FF for the high-mobility case as a function of GB recombination velocity when the GB potential is 0 (square), 200 (circle), 400 (triangle), and (asterisk).
The recombination rate , hole concentration , and electron concentration along the direction (parallel to the plane of the junction) at a depth of from the CIGS/CdS interface for (a) an applied bias of in the dark and (b) no applied bias and AM 1.5 illumination. The GB is located at .
The efficiency for the low-mobility case when the GB potential is 0 (square), 200 (circle), 400 (triangle), and (asterisk).
The photocurrent collected when the electron beam is centered at different depths relative to the CIGS/CdS junction.
The diffusion length calculated from EBIC simulations for the (a) high-mobility case and (b) low-mobility case.
The spectral IQE for different GB potentials.
The PL decay curves for high-mobility absorber layers where the GB recombination velocity is . The solid and dashed lines correspond to a GB potential of 0 and , respectively.
(Color online) The dashed line represents the equilibrium hole concentration. The solid lines represent the excess electron distributions 0, 0.1, 0.4, 1, 4, and after the laser pulse, respectively.
The PL decay time for different GB recombination velocities and potentials for the (a) high-mobility case and (b) low-mobility case.
The ratio of the photocurrent generated by the NSOM tip when it is positioned directly over the GB to when it is centered on the GI for (a) frontside illumination and (b) backside illumination.
The basic material parameters used in the high-mobility simulations. The symbols in the left-hand column under bulk properties represent the band gap, electron and hole mobilities, dielectric constant, net carrier concentration, effective density of states for the conduction and valence bands, conduction-band offset between adjacent layers, deep state concentration, electron and hole capture coefficients for these deep states, and the energy level of these deep states relative to the valence band, respectively. , , and represent the Schottky barrier height and surface recombination velocities at the front and back contacts, respectively.
The GB potential at corresponding to different GB acceptor and donor concentrations.
Article metrics loading...
Full text loading...