Solar cell classification

Solar cells, also known as photovoltaic cells, are devices that convert solar radiation directly into electrical energy. The solar cell module is packaged by such a device, and a certain number of components are combined into a solar cell array of a certain power as needed, and matched with an energy storage device, a measurement control device, and a DC-AC conversion device to form a sun. Battery power generation systems, also known as photovoltaic power generation systems.

The core component of solar photovoltaic power generation is solar cells. The development history of solar cells has passed a long history of more than 160 years. From the perspective of overall development, basic research and technological progress have played a positive role. So far, the basic structure and mechanism of solar cells have not changed.

1. Classification by structure

Ø homogenous solar cells Ø heterojunction solar cells Ø Schottky solar cells

2. Classified by material

ØSilicone solar cell ØMulti-component thin film solar cell ØOrganic compound solar cell

Ø sensitized nanocrystalline solar cell Ø polymer multilayer modified electrode solar cell

3. Classified by work style

Ø Flat solar cell Ø concentrating solar cell Ø split solar cell

p** generation: monocrystalline silicon and polycrystalline silicon, accounting for 89.9% of the solar cell product market. **The generation of solar cells is based on silicon wafers, mainly using single crystal silicon and polycrystalline silicon. Among them, the conversion efficiency of single crystal silicon cells can reach 18-20%, but the production cost is high.

The second generation of p: thin film solar cells, accounting for 9.9% of the market of solar cells, the second generation of solar cells based on thin film technology, mainly using amorphous silicon and oxide as materials. The efficiency is lower than that of **, and the conversion efficiency of ** is 13%, but the production cost**.

Third generation: compound thin film solar cells such as copper indium selenide (CIS) and thin film Si-based solar cells. Mainly in the state of laboratory production, due to its high efficiency and low cost, there are potentially huge economic effects.

1. Silicon solar cells can be divided into:

1). Monocrystalline silicon solar cells

2). Polycrystalline silicon thin film solar cell

3). Amorphous silicon thin film solar cell

Monocrystalline silicon solar cell

The monocrystalline silicon solar cell is a solar cell made of a high-purity single crystal silicon rod, and its conversion efficiency is **, and the technology is also the most mature. High performance monocrystalline silicon cells are based on high quality single crystal silicon materials and related thermal processing processes.


Amorphous silicon thin film solar cell

The silicon used in the amorphous silicon thin film solar cell is a-Si. The basic structure is not a pn junction but a pin junction. Boron is doped to form the p region, and phosphorus is doped to form the n region, where i is a non-impurity or lightly doped intrinsic layer.


Salient features:

Ø Low cost of materials and manufacturing processes.

Ø The production process is low temperature process (100-300 °C), and the energy consumption is low.

Ø Easy to form large-scale production capacity, production can be fully automated.

Ø Many varieties and wide applications.

There is a problem: the optical band gap is 1.7eV → insensitive to long-wavelength regions → low conversion efficiency

Photoinduced decay effect: Photoelectric efficiency decays with the continuation of illumination time

Solution: The laminated solar cell is prepared by sinking one or more pin sub-cells on the prepared pin single-junction solar cell.

Production methods: reactive sputtering, PECVD, LPCVD.

Reaction gas: H2 diluted SiH4