High efficiency solid-state photovoltaic device due to inhibition of interface charge recombination

The performance of solid-state dye-sensitized solar cells based on spiro-MeOTAD was considerably improved by controlling charge recombination across the interface of the heterojunction. This was achieved by blending the hole conductor matrix with a combination of 4-tert-butylpyridine $\mathrm{(t}\mathrm{BP})$ and ${\mathrm{Li[CF}}_{\mathrm{3}}{\mathrm{SO}}_2{]}_2\mathrm{N}.$ Open circuit voltages $U_{\mathrm{oc}}$ over 900 mV and short circuit currents $I_{\mathrm{sc}}$ up to 5.1 mA were obtained, yielding an overall efficiency of 2.56% at AM1.5 illumination. These values have been fully confirmed at the National Renewable Energy Laboratories for a device with an active area of 1.07 cm², signifying a dramatic improvement compared to previously reported values for a similar device.