Cu2ZnSnSxSe4-x (CZTSSe) has drawn world-wide attention due to its promising performance and earth-abundant components. So far, the state-of-the-art CZTSSe thin film solar cells have reached up to 12.0% power conversion efficiency via a hydrazine-assisted deposition approach. However, it is generally difficult to get efficiency above 12% and the PCE of CZTS solar cells is still far below the physical limit, known as the Shockley-Queisser (SQ) limit, of about 31% under terrestrial conditions.
In this presentation, a new world record 12.6% CZTSSe thin film solar cell (performance independently certified) will be presented with extensive device characterization. The improvement of device performance is primarily due to the reduction of Voc deficit by ~50 mV. The depletion width xd and diffusion length Ld of the 12.6% CZTS solar cell, as deduced from C-V and voltage-dependence of IQE, are 0.15 ± 0.03 um and 0.75 ± 0.15 um, respectively, which are in good agreement with the 1-μm current-collection depth deduced from EBIC.
The capacitance analysis indicates a substantial component of interfacial recombination within the record device. These results continue the recent trend of substantial increases in CZTSSe device performance improvements from 6.7% (2008) to 9.7% (2010) and 11.1% (2012), indicating the substantial promise of this new thin-film PV materials system.