Photoluminescence Quantum Yield (PLQY)
PLQY is a direct ratio of the integrated photoluminescence emission to the integrated absorbance. This measurement can lead to insights into the ratio of radiative to non-radiative pathways with a semiconductor system. As the open circuit voltage is limited by the non-radiative pathways with a solar cell, PLQY can provide information on the loss mechanisms contributing to the loss in open circuit voltage.
Our Hamamatsu Quantaurus-PLQY apparatus is equipped with an 84 mm integrating sphere and dual photonic multichannel analysers allowing for PLQY to be measured between 350-1100 nm and absolute yield to be determined below 2%. A 150 W Xe lamp can be used in conjunction with a monochromator to measure PLQY as a function of pump wavelength. Further we have equipped our Quantaurus with a high power Xe lamp and adjustable band pass filters creating a broadband excitation source, enhancing our signal to noise and absolute yield measurements to below 1%.
Figure 1: Hamamatsu Quantaurus-QY absolute photoluminescence quantum yield spectrometer.
Figure 2: (Upper Panel) Broadband Excitation and photoluminescence spectrum of 1% PCDTBT:PCBM. (Lower Panel) PLQY as a function of monochromatic excitation wavelength for various blends of PCDTBT:PCBM.