Improved performance of a-Si:H solar cell by using up-conversion phosphors.

Up-conversion is a promising technique for harvesting sub-band-gap photons in photovoltaic devices. The implementation and characterization of rare-earth doped up-converters on a-Si:H solar cells are investigated. Three up-conversion phosphors, β-NaYF 4 :Yb 3+ 20%/Er 3+ 1%, β-NaYF 4 :Yb 3+ 25%/Ho 3+ 1% and β-NaYF 4 :Yb 3+ 60%/Tm 3+ 0.5%, are developed and employed as low energy convert materials for a-Si:H solar cells. Two different ways of adhering the up-converter to the a-Si:H solar cell have been implemented: by dissolving the powder in the polydimethylsiloxane (PDMS) and by compressing it into solid slice with a tablet pressing machine. The performance of a-Si:H solar cells integrating the up-converters is investigated under both 980 nm infrared laser diode and simulated solar light source (AM1.5G) illumination. The Current-Voltage measurements reveal that the β-NaYF 4 :Yb 3+ 20%/Er 3+ 1% up-conversion phosphor performs both up-conversion and scattering functions in improving the overall performance of a-Si:H solar cell. [ABSTRACT FROM AUTHOR]