Inclusion of CdSe quantum dots on the P-doped emitter of Si solar cells

We investigated Cadium Selenide quantum dots embedded in the Si solar cell in order to improve the efficiency of conventional Si solar cell. CdSe quantum dots with 3 to approximately 4 nm size were printed on the phospho-silicate glass layer grown over the emitter surface of p-n junction Si solar cells during the phosphorous diffusion process. Ohmic contact was formed by the contribution of nanoparticles at the Si emitter in spite of the existance of phospho-silicate glass layer. The enhanced light absorption due to the quantum dots was ranged from 500 to 600 nm where the CdSe nanodots have the corresponding emission wavelength of 560 nm. The efficiency of reference solar cell with the glass layer was measured to be 1.0% and it was increased to 12.72% for the reference sample without the glass layer. Furthermore, the efficiency of CdSe quantum dot sample was measured to be 13.6%. This indicates that the quantum dots play the roles of both the formation of tunneling channel and the enhancement of the light conversion efficiency in the visible spectral range.