18.+How+efficient+can+organic+PV+cells+be

18.+How+efficient+can+organic+PV+cells+be - MSE 343 May 19,...

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MSE 343 May 19, 2008 How Efficient Can Organic Solar Cells Be?
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500 1000 1500 2000 2500 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 Spectral Irradiance (W/m 2 /nm) Wavelength [nm] Opening thoughts E As E g goes up, V OC goes up, but the number of photons absorbed goes down. For a conventional solar cell, the theoretical limit is 32 % and is achieved for a 1.4 eV band gap. For excitonic solar cells, the limit is lower because energy is lost splitting the exciton.
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Calculating limits: The current Very Safe We have seen that it is possible to have an EQE of 65 % over a reasonably wide spectral region just above band gap. Likely attainable We do not yet know of any reason why we can’t achieve an EQE of 85 %. The Limit One cannot do better than an EQE of 100 % for photons that have more than the band gap energy (that is without multiple exciton generation techniques). Exceeding 85 % is tough when reflection and absorption in the electrode are considered.
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18.+How+efficient+can+organic+PV+cells+be - MSE 343 May 19,...

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