Product Definition:

Perovskite cells are a new type of compound thin-film solar cell that uses perovskite-type materials as a light-absorbing layer. They belong to the third generation of solar cells and can be categorized as pure perovskite cells or perovskite tandem cells. Perovskite cells can be stacked with either crystalline silicon cells or thin-film cells, with a theoretical maximum stacking capacity of four layers. With technological advancements, full perovskite tandems are also possible, potentially leading to complete independence from crystalline silicon cells. Perovskite materials possess numerous excellent properties, such as high absorption coefficient, high carrier mobility, and high defect tolerance. These properties contribute to a range of advantages for their cells, including simple preparation, low cost, and ultra-light and ultra-thin design. Furthermore, by optimizing their chemical composition, perovskite materials with varying characteristics can be produced for diverse applications, such as semi-transparent solar cells and colored photovoltaic glass. The bandgap of these materials can be tuned by varying the types and proportions of their constituent substances, enabling them to cover a wide spectral absorption range extending into the infrared region. They also possess the advantages of long carrier diffusion distances and high mobility.

Features:

1.Efficiency Advantage

According to data from the Qianzhan Industry Research Institute, the theoretical efficiency limit for crystalline silicon cells is 29.43%, for TOPCon cells is 27.5%, and for HJT cells is 28.2%-28.7%. Currently, the efficiency of TOPCon cells in mass production has reached 24.6%, and the average efficiency of HJT cells in mass production has exceeded 24%. The room for improvement in the efficiency of crystalline silicon cells in mass production is limited, and a bottleneck may be reached within the next decade. Perovskite cells, on the other hand, offer rapid efficiency improvements and a high ceiling. Single-junction cells can reach 31%, exceeding the limit of crystalline silicon cells. Dual-junction stacks can reach 40%, and triple-junction stacks can reach 50%.

2. Cost Advantage

The perovskite photovoltaic industry chain is shorter than that of crystalline silicon and inherently features an integrated approach. By sourcing chemical raw materials, final module production can be completed and delivered from a single factory, significantly shortening the production lead time and reducing overall costs. Of particular note, the cost of perovskite raw materials typically accounts for only 5-8% of the cost of perovskite modules, and their price is stable, far lower than the silicon material in crystalline silicon modules, which accounts for over one-third of the cost and experiences significant price fluctuations. Furthermore, according to GCL Optoelectronics, as perovskite modules scale up, module costs will drop to RMB￥0.7-0.75 /W when production capacity reaches 1GW, module efficiency reaches 17%, and cell sizes reach 2.4m².

Challenges to Commercialization:

1. Large-Area Fabrication

The conversion efficiency of perovskite cells decreases significantly with increasing area. The main reasons include:

1) non-uniform deposition of thin films over large areas;

2) perovskite degradation at the edges of the P2 scribe line;

3) dead zones in the cell subcell connections; and

4) increased series resistance and decreased parallel resistance in the module. Large-scale fabrication of perovskite cells faces numerous challenges, the most significant of which is perovskite film fabrication.

2. Stability

Currently, the maximum continuous illumination duration of perovskite cells is approximately 10,000 hours. Based on an average sunlight duration of 4 hours, the theoretical lifespan is only 6.8 years, significantly lower than the 25-year theoretical lifespan of crystalline silicon cells. Stability is the biggest bottleneck for perovskite cells, and no effective solution currently exists. The reasons are:

1) Their structure: perovskites are ionic structures with weak bonds;

2) Reaction characteristics: the perovskite formation temperature is low and the energy required for reverse decomposition is low;

3) The external environment: water, oxygen, and sunlight can easily damage the crystal structure.