Carrier Transport and Behaviour of Hybrid Photovoltaic Solar Cell – Inorganic and Organic Nanocrystals Devices

A. Islam, A.T. Aynul
UESTC, Glasgow College, China, University of Glasgow, UK,
United Kingdom

Keywords: photovoltaic (PV) solar cell, core-shell CdSe/ZnS nanocrystal, organic and inorganic nanomaterials, (I - V) characteristics, open circuit voltage, short-circuit current density, fill factor, photolithography (PhL) system, air mass (AM 1.5) illumination


Abstract: Photovoltaic (PV) solar energy has the possibility to produce as much as 15% of our electricity needs by incorporation of PV into buildings. Some university labs and industrial partners have been working together to find new material solutions to reduce the cost of PV manufacture and improve solar conversion efficiency. The next generation of thin film PV modules will develop conversion efficiencies closer to those developed today by crystalline silicon modules while using far less material. This will minimize cost and improve material sustainability in extensive manufacture. Further research into this field will bring a more refined understanding of carrier transport in polycrystalline thin films. The basic principles of the solar cell (designed as p-n junction diode) were derived from the equations describing the dynamics of holes and electrons in semiconductors. This moved forward to the definition of the solar cell figures of merit – the open-circuit voltage (VOC), the short-circuit current (ISC), the fill factor (FF), and the cell efficiency (η). The most important two key factors determining PV solar cell efficiency are electron–hole pair generation and recombination, discussed and identified in this paper extensively. In this experiment, the core-shell CdSe/ZnS nanocrystal is used to improve photon efficiency of hybrid solar cells over a wide spectral range between 330 nm to 1200 nm. Absorption spectra and current/voltage (I/V) characteristics were measured in the dark as well as under illumination at a simulated air mass illumination (AM1.5) of 100 mW/cm-2. The device of nanocrystal/polymer-blend solar cell developed the current efficiency to 6% at an open circuit voltage (Voc) of 0.8 V, short-circuit current densities (Isc) of 0.004 A 〖cm〗^(-2), and fill factor (FF) of 0.38. Inorganic semiconductors are well fitted to the development of optoelectronic devices due to their simple processability of optical transition.