Fully-ambient-processed mesoscopic semitransparent perovskite solar cells by islands-structure-MAPbI3-xClx-NiO composite and Al2O3/NiO interface engineering

Perovskite solar cells (PSCs) because of low-cost fabrication and high performance have shown superb potential for the next-generation photovoltaic application. For the potential applications of photovoltaic technologies, semitransparent PSCs are also highly attractive and of commercial interest to develop building-and tandem-integrated solar cells. Here, we present fully-ambient-processed stable and mesoscopic semitransparent PSCs by non-continuous islands-structure-CH3NH3PbI3-xClx-NiO nanoparticles (MAPbI(3-x)Cl(x)-NiO NPs) composite and interface engineering by inserting Al2O3/NiO between TiO2 and MAPbI(3-x)Cl(x)-NiO composite layers in a device configuration of FTO/c-TiO2/mp-TiO2/Al2O3/NiO/islands-structure-MAPbI(3-x)Cl(x)-NiO/spiro-OMeTAD/Au. Except for the islands-structure-MAPbI(3-x)Cl(x)-NiO capping layer, a uniform and thicker and transparent TiO2/Al2O3/NiO/MAPbI(3-x)Cl(x) composite layer is formed, which can effectively reduce photocurrent density loss and interface recombination. Interestingly, the optimized semitransparent PSCs showed hysteresis-free performance. The average visible transmittance (AVT) of MAPbI(3-x)Clx-NiO NPs composite film was ranged from 18% to 56% and the corresponding device PCE changed from 17.51% to 12.47%. The PSCs without encapsulation showed an excellent air stability over 270 days with retaining similar to 98% of its original V-oc, similar to 96% of J(sc), similar to 97% of FF and similar to 93% of PCE under ambient condition (25-30 degrees C and 45-50% humidity). Finally, we achieved semitransparent device of PCE = 10.06%, corresponding to AVT = 27%.