Self-cleaning transparent Cu2Y2O5/Tb:Bi2Sn2O7 quantum dots/Bi2O3 pn junction for photovoltaic enhancement via synergism of up-conversion fluorescence and surface hydrophobicity.

The competitiveness between photovoltaic conversion efficiency (PCE) and transparency would be the bottleneck of transparent device for actual applications, as well as the high maintenance cost. In this work, the self-cleaning transparent device in interfacial Tb:Bi 2 Sn 2 O 7 QDs modified Cu 2 Y 2 O 5 /Bi 2 O 3 pn junction is prepared via a simple approach of sol-gel-hydrothermal method. The obtained Cu 2 Y 2 O 5 /Tb:Bi 2 Sn 2 O 7 QDs/Bi 2 O 3 exhibits high transmittance of ∼85 %, obvious photovoltaic enhancement of ∼2.0 × 103-folds (PCE of ∼1.17 %), stable output in 5 months cycles and a good self-cleaning via the hydrophobicity (contact angle of ∼123.4°). It's mainly attributed to the Tb:Bi 2 Sn 2 O 7 QDs and lamellar Bi 2 O 3 array. Besides appropriate potential and high quantum yield, the Tb:Bi 2 Sn 2 O 7 QDs, with the synergism of up-conversion fluorescence and interface/surface optimization, can improve the carrier kinetic equilibrium for achieving PCE-transparency balance, as well as increasing p-type conductivity through the synergism of Cu+/Cu2+ and interstitial oxygen. Moreover, the regular lamellar array can enhance solar efficiency via optimized surface, meanwhile achieving self-cleaning via the surface hydrophobicity and enhancing structural stability via the regular interval, making it being advantageous in actual applications of energy and information field, including windows, smart devices, etc. [ABSTRACT FROM AUTHOR]