Photosensitive cell technology innovation driven by semiconductor technology

A photosensitive cell, also known as a photovoltaic cell or light-sensitive cell, is a delicate device that efficiently converts light energy into electrical energy. Its core principle involves the use of photosensitive materials, which absorb light and generate an electric current in the process of photogenerated charge separation. Photosensitive cells are widely used in many fields, including solar power generation, photoelectric sensing, optical communication and light control.

The working principle of photosensitive cells can be divided into the following steps:

1. Light absorption: Photosensitive materials have energy level structures that match the energy of photons, so they can effectively absorb light. When light strikes a photosensitive cell, the photons excite electrons in the photosensitive material.

2. Generation of carriers: After absorbing photons, electrons in the photosensitive material will jump from the valence band to the conduction band to form free electrons. At the same time, the holes in the conduction band will also be filled, forming carrier pairs.

3. Charge separation: Photogenerated electrons and holes will be separated inside the photosensitive material. This process is accomplished by an electric field or heterostructure within the material, causing electrons to move toward an electrode of one polarity and holes to move toward an electrode of the other polarity.

4. Current output: By connecting to an external circuit, the generated electrons and holes will flow through the wire to form a current. This current can be used for power supply, charging, or other power needs.

The working principle of photosensitive cells is based on key processes such as light absorption, carrier generation and charge separation, and therefore can effectively convert light energy into usable electrical energy.

There are some differences between photosensitive cells and solar cells:

1. Structure and materials: Photosensitive cells usually use thinner photosensitive materials, such as silicon, cadmium selenide (CdS) or cadmium indium sulfide (CIS). Solar cells, on the other hand, are usually made of thicker crystalline silicon or other composite materials.

2. Application scope: Photosensitive cells are mainly used in photoelectric sensing, light control, optical communications and other fields. Due to its small size and flexibility, photosensitive cells are suitable for various special shapes and curved surface installation requirements, and are widely used in photoelectric sensors, photoelectric switches, optical fiber communications and other equipment.

3. Conversion efficiency: Solar cells usually have high photoelectric conversion efficiency. The conversion efficiency of solar cells currently available on the market is generally between 15-25%, or even higher, depending on the materials and technology used. The conversion efficiency of photosensitive cells is relatively low because they usually use thin photosensitive materials and have a narrow response to the spectral range.

4. Environmental adaptability: Solar cells have good stability and durability in outdoor environments. They are waterproof, dustproof and UV-resistant and can adapt to various harsh climatic conditions. Photosensitive cells have relatively poor environmental adaptability, especially high sensitivity to humidity and temperature, and may suffer performance degradation in extreme environments.