The first generation solar cells based on silicon widely used for photovoltaic power generation are costly to produce and their efficiency decreases rapidly at higher temperatures. The second generation thin films based solar cells using cadmium telluride (CdTe) and copper indium gallium di-selenide (CIGS) materials lack high efficiency and are toxic and not environmentally friendly. To overcome these issues, third generation solar cells are being developed which are called dye sensitized solar cells (DSSC) and perovskite solar cells (PSC). However, due to poor long-term stability, narrow spectral absorption range, charge carrier transportation and collection losses and poor charge transfer mechanism for regeneration of dye molecules, the development of DSSCs over the last two decades is almost stagnant. Here the main challenge is how to improve the performance of DSSCs. We applied various methods, by using new electrode materials with nano-structures, different dye compositions with promising nanocomposites and metal quantum dots as well cost effective hole transporting materials. In addition different nanostructured materials were investigated for photo-anodes and counter-electrodes, including metal oxides and highly mesoporous carbon (HMC) to achieve better efficiency of DSSCs by focusing on materials which absorbs over a broad band of solar spectrum (visible and near infrared) and are less expensive and stable.
On the perovskite side, our focus is to prepare perovskite bulk and thin single crystals which are grown using Inverse thermal crystallization method. Three types of single crystals were grown including pure 3D using methylammonium lead iodide (MAPbI3), (2D/3D using butylammonium mixing with methylammonium lead iodide (BAI: MAPbI3), and 2D/3D with propylammonium mixing with methylammonium lead iodide (PAI: MAPbI3). The single crystals were characterized using advanced analytical technique such as optical microscope for optical images, scanning electron microscope (SEM) for electron images, X-ray diffraction (XRD) and spectrofluorometry. Finally Single crystals perovskite solar cells were fabricated which exhibited higher efficiency as compared to the poly crystalline based solar cells. In addition to the development of third generation solar cells, our group is also working on thermoelectric materials for energy harvesting based on Seebeck effect & refrigeration based on Peltier effect and on energy storage devices likes super-capacitors. The authors are thankful to KFUPM for supporting this work under project # RG 162002 and K.A. CARE under project # KACARE182-RFP-02