The conversion rate of silicon solar cells is 27%, has the perovskite cooled down?

On November 19th, Longi Green Energy announced at the 16th China New Energy International Expo and Summit that it had received the latest certification report from the Hamelin Solar Energy Research Institute (ISFH) in Germany. Longi Green Energy's independently developed silicon heterojunction cell has a conversion efficiency of 26.81%, setting a current record for the highest efficiency of silicon-based solar cells worldwide.

This is the latest world record since a Japanese company set a record of 26.7% efficiency for single crystal silicon cells in 2017, and it is also the first time in the history of photovoltaics that a Chinese solar technology company has set a world record for silicon cell efficiency.


What is a heterojunction?


The so-called heterojunction refers to the junction layers of different materials, which use different materials to absorb light from different spectra, thereby greatly enhancing the efficiency of the battery pack.
Heterojunction batteries were first developed by Sanyo Corporation in Japan in 1990 and registered as trademarks. Subsequently, companies entering the heterojunction field adopted different terms to avoid patent disputes, such as HJT/SHJ/HDT. Although there are slight differences in English names and abbreviations, their meanings represent intrinsic thin film heterojunction batteries.
Structurally, it is generally based on N-type silicon wafers, with transparent conductive oxide film (TCO), P-type amorphous silicon film, and intrinsic hydrogen rich amorphous silicon film on the front side in sequence; On the back of the battery, there are TCO transparent conductive oxide film, N-type amorphous silicon film, and intrinsic amorphous silicon film in sequence.
In addition, the manufacturing process of heterojunction batteries is also relatively simple. The thin film is formed by deposition, and finally metal electrodes are prepared on both sides of the battery through screen printing or electroplating technology. After low-temperature curing process, the manufacturing of heterojunction batteries is completed.
In materials with higher conversion rates, heterojunctions are relatively easy to mass produce and have less environmental impact.