Outcome/Output: | 1. The BHJ solar cell of P3HT: CdSe/QDs and P3HT: SWCNT: QDs had been made of 5 and 5.5% efficient, respectively. However, target is to further increase the efficiency to at least 7% and therefore work on new materials PCDTBT has been started. In bulk heterojunction (BHJ) solar cell, P3HT: CdSe/QDs and P3HT: SWCNT: QDs based cell was replaced with PCDTBT, its characterization and fabrication with solar cell was done. AFM was purchased, installed and results were published with P3HT based device. PCBM structure a BHJ is induced using the process of thermal inter-diffusion. The absorption measurements on the bilayer structure shows that the absorption coefficient increases and the absorption spectrum becomes broader in the annealed device. Also, the photoluminescence studies of the annealed film/device are under study. Better PL quenching effect showing a significant transfer of electrons to the QDs have been seen. The process of inter-diffusion is highly sensitive to the temperature at which the samples are annealed. Process optimization of the temperature and duration of the diffusion process, increase the PCE and fill factor of solar cell samples is done.
2. The hybrid PV device has number of advantages over the OPV devices consisting of PCDTBT: PCBM BHJ. To further improve the device, studies of PCDTBT:QD solar cells and PCDTBT:QD:SWNT solar cells is being done.
i. The SWCNT and QDs provide an additional source of absorption of solar spectrum in the visible as well as infrared region (tuning possible with size of QD).
ii. Multiple excitons can be created by the QDs by the process of impact ionization.
iii. Under favourable condition the exciton dissociation will be fast.
3. Some of these processes verified also. |