Surface polarity engineering of ZnO layer for improved photoluminescence of CsPbBr3 quantum dot films

The surface polarity of nanocrystalline ZnO film, a typical electron transport material in optoelectronics , is chemically modified using self-assembled monolayer (SAM) of phenethyl trichlorosilane (PETS). The surface treatment is proved to generate a hydrophobic surface by removing the hydroxyl groups on the oxide layer, which reduces the emission quenching of the subsequent CsPbBr 3 quantum dot film. In addition, the surface polarity was engineered with varying PETS concentration, thereby contribute to an increased photoluminescence quantum yield (PLQY) by up to 50%. Meanwhile, the thermal stability of photoluminescence was enhanced showing a wide-range temperature tolerance up to 140 °C.