Down-conversion in Tm3 +/Yb3 + doped glasses for multicrystalline silicon photo-voltaic module efficiency enhancement

Efficiency enhancement of a multicrystalline silicon solar cell using down-conversion of Tm3 + and Yb3 + doped silicate glasses was investigated. Na2O–CaO–SiO2 glasses doped with Tm3 + or Tm3 + and Yb3 + were prepared. Distributed Bragg Reflector (DBR) coatings were sputtered on the glass surface to control the transmission and reflection of the desired portion of the solar spectrum. These were placed on a multicrystalline silicon solar cell in combination with a solar spectrum simulator. The efficiency of solar cell with Tm3 + or Tm3 + and Yb3 + doped glasses increased compared to as-prepared glass without rare-earth addition. The efficiency of solar cell with rare earth doped glasses was re-measured three times with same samples, and the real efficiency enhancement can be proved. The potentials, limitations and future perspectives of rare-earth doped glasses with DBR structure on the efficiencies of PV modules were discussed.