Application of organic photoelectric materials in the field of organic solar cells

Organic optoelectronic materials are a class of organic materials with photoelectric activity, which are widely used in organic light-emitting diodes, organic transistors, organic solar cells, organic memory and other fields. Among these, organic light-emitting diodes and organic solar cells are the most widely studied. Let us talk about the knowledge of organic solar cells today.

What is a solar cell?

Solar cells are semiconductor devices made using semiconductor photovoltaic effects and are also an application of ionizing radiation effects. Solar cells are widely used in space and on Earth. They provide a long-term power supply for satellites and are an important source of energy for the Earth because they can convert sunlight directly with high conversion efficiency into electrical energy, it can provide almost eternal power with little pollution and low-cost.

How organic solar cells work

An organic solar cell (OSC) mainly refers to a device that utilizes an organic semiconductor material having a conjugated structure as a lightness f to absorb the energy of a photon and convert it into electrical energy. First, the organic molecule is excited from the state to the excited state, at which time an electron-hole pair (exciton) will be generated inside the molecule. Excitons have a certain lifetime and will migrate between molecules and molecules. When excitons migrate to the interface of the acceptor with energy level mutations, electron-hole charge transfer states will occur, and then separated into isolated electrons and holes to form a delocalized carrier. Finally, the carrier forms a current under the action of the built-in electric field, thereby realizing the conversion of light energy to electric energy.

Dye-sensitized solar cells bring revolutionary innovation

Compared with the photoelectric conversion efficiency of inorganic silicon solar cells, the light conversion efficiency of organic solar cells still remains at a relatively low level. Therefore, the core of research on organic solar cells is to improve the photoelectric conversion efficiency of batteries. The photoelectric conversion efficiency of organic solar cells has been greatly improved by designing reasonable device structures, improving interface morphology, and increasing the degree of crystallization of polymers. In order to make more effective use of the infrared part of sunlight, the research on narrow-bandgap polymer organic semiconductors has begun to attract people's attention, becoming a new hot spot of organic solar cells by using benzodithiophene narrow band gap polymers. YangYang’s team from UCLA achieved organic solar cells with photoelectric conversion efficiencies exceeding 7%. In 1991, Gratzel proposed a novel photovoltaic cell, DyeSensitized SolarCell (DSSC), which is a photoelectrochemical cell using a sensitized titanium dioxide porous nanophotoanode with a carboxylic acid bipyridylium(II) complex. Development has brought revolutionary innovation. The current maximum efficiency of dye-sensitized solar cells is 11.04%, and there is still room for improvement.

Edited by Suzhou Yacoo Science Co., Ltd.