What are heterojunction solar cells (HJT)?

Heterojunction solar cells (HJT), variously known as Silicon heterojunctions (SHJ) or Heterojunction with Intrinsic Thin Layer (HIT), are a family of photovoltaic cell technologies based on a heterojunction formed between semiconductors with dissimilar band gaps.

How do heterojunction solar cells work?

In the case of front grids, the grid geometry is optimised such to provide a low resistance contact to all areas of the solar cell surface without excessively shading it from sunlight. Heterojunction solar cells are typically metallised (ie. fabrication of the metal contacts) in two distinct methods.

What is a silicon heterojunction solar cell?

Silicon heterojunction (HJ) solar cells are one such passivated contact cell. HJ cells are typically formed with an n-type bulk between intrinsic amorphous silicon (a-Si) layers. The passivating contacts are then completed by a p-type doped a-Si layer for the hole contact and an n-type doped a-Si layer for the electron contact.

How effective is hydrogenated intrinsic amorphous silicon in SHJ solar cells?

In SHJ cells, hydrogenated intrinsic amorphous silicon is very effective at passivating defects existing at the absorber surface. Understanding the behaviour of defects, and how they interact with hydrogen over time and in manufacturing processes, is crucial for maintaining the stability and performance of SHJ solar cells.

What is a front-junction solar cell?

A "front-junction" heterojunction solar cell is composed of a p–i–n–i–n -doped stack of silicon layers; the middle being an n -type crystalline silicon wafer and the others being amorphous thin layers.

What is a multi-junction solar cell?

To further enhance the solar cell's performance, the multi-junction solar cell was introduced, composed of multiple p-n junctions of different semiconducting materials. The multiple p-n junction in the solar cell allows the use of additional solar spectrum wavelengths to improve the cell’s efficiency .