Green upconversion improvement of TiO2 codoped Er3+-Yb3+ nanoparticles based thin film by adding ALD-Al2O3 for silicon solar cell applications

This paper investigates the upconversion luminescence modification of codoped nanoparticles with lanthanides ions based thin films through adding a coating. First, these composed Er3+-Yb3+ co-doped anatase-TiO2 are prepared using spin coating technique supported by design experiment (DOE) approach Hadamard matrix order 4 to improve deposition conditions. For step, different thicknesses Al2O3 layer realised thermal atomic (T-ALD) onto surface films. The results show that ALD-Al2O3 can benefit properties Thin (10 nm) coated stack exhibits similar as uncoated film but insures also their stability. Meanwhile, for 100 nm coating, enhancement green emission 98% at expense red compared sample is observed. promising be applied in photovoltaics field.