Author/Authors :
Johnson، نويسنده , , D.C. and Ballard، نويسنده , , I. and Barnham، نويسنده , , K.W.J. and Bishnell، نويسنده , , D.B. and Connolly، نويسنده , , J.P. and Lynch، نويسنده , , M.C. and Tibbits، نويسنده , , T.N.D. and Ekins-Daukes، نويسنده , , N.J. and Mazzer، نويسنده , , M. and Airey، نويسنده , , R. and Hill، نويسنده , , G. and Roberts، نويسنده , , J.S.، نويسنده ,
Abstract :
Strain-balanced quantum well solar cells (SB-QWSC) extend the photon absorption edge beyond that of bulk GaAs by incorporation of quantum wells in the i-region of a p–i–n device. The addition of a distributed Bragg reflector (DBR) can substantially increase the photocurrent with little or no detriment to the dark-current. Experimental results are presented that show improvements of DBR cell efficiencies over SB-QWSCʹs without DBRʹs. In addition, at high dark-current levels appropriate to high concentration, we observe that the dark-currents of the SB-QWSCʹs exhibit ideal diode behaviour. We present evidence that the ideality n = 1 dark-current is reduced in the DBR cells and discuss the possible efficiency improvements if the dark-current is radiatively dominant.
Keywords :
Quantum well cells , Distributed Bragg reflector (DBR) , Strain balance , InGaAs , GaAsP
