Solar cells, modeling quantum efficiency

The solar cell is the basic unit of the photovoltaic generator. The solar cell is the device that transforms the sun s rays or photons directly into electricity. There are various models of solar cells made with different technologies available in the market today. These models have varying electrical and physical characteristics depending on the manufacturer. The photocurrent generated by a solar cell under illumination at short circuit is dependent on the incident light. To relate the photocurrent density, to the incident spectrum, we need the cell s quantum efficiency (QE). QE (E) is the probability that an incident photon of energy E will deliver one electron to the external circuit. Then,... 

Many nanoscale energy conversion devices, like dye-sensitized and pol5mer-based solar cells, rely on efficient interfacial electron transfer processes. Multiscale modelling of such devices ultimately involves length-and time-scales that scan many orders of magnitude, ranging from ultrafast molecular-scale quantum phenomena such as photoinduced electron transfer, via mesoscopic properties such as charge transport, to macroscopic device performance such as I-V characteristics. 

Watkins P. K., Walker A. B. and Verschoor G. L. B. (2005), Dynamical Monte Carlo modelling of organic solar cells the dependence of internal quantum efficiency on morphology , A/ano Lett. 5, 1814—1818. 

Slooff LH, Veenstra SC, Kroon JM, Moet DJD, Sweelssen J, Koetse MM (2007) Determining the internal quantum efficiency of highly efficient polymer solar cells through optical modeling. Appl Phys Lett 90 143506... 

Gonzalez-Pedro V, Xu X, Mora-Ser6 I, Bisquert J (2010) Modeling high-efficiency quantum dot sensitized solar cells. ACS Nano 10 5783-5790... 

If the carrier collection efficiency is very good, then the photocurrent, y ph, is determined by the light absorption and charge injection features that are measured by Incident Photon to Current conversion Efficiency (IPCE), also known as the External Quantum Efficiency (EQE) [18]. Examples of the absorption spectra of efficient dyes are shown in Fig. 3 [19], and the corresponding IPCE is shown in the figure together with the final photovoltaic performance. In this type of highly efficient DSC, the measured current can indeed be viewed as completely decoupled from recombination, as in the model of (19). The convolution of IPCE with the solar spectrum describes very well the actual value of /ph. However, in cells with low collection efficiency, one should be careful to calculate correctly the collection... 

---