Enhanced Efficiency of PTB7 : PC₆₁BM Organic Solar Cells by Adding a Low Efficient Polymer Donor

Figure 2

Photoluminescence spectra of films of the PTB7 : pBTTT (0.1 : 0.9) blend and of the same blend upon addition of PC₆₁BM, deposited over quartz substrates, following excitation at the maximum of absorption of pBTTT. For comparison, the spectrum of the bare quartz is also shown.