Topcon Solar Module

Manufacturing back-field: Utilizing potassium hydroxide (KOH), the process removes saw damage during the cutting of c-Si wafers. Diffusion is then employed to form a layer of boron tribromide (BBr) on the cell front.

Cleaning: Wet chemistry is applied to remove boron tribromide from the backside. Nitric acid and hydrofluoric acid (HF/HNO) are used to eliminate impurities, concluding with the production of an ultra-thin oxide layer through wet chemical impregnation.

Growth of n-a-Si layer: A phosphorus-doped amorphous silicon (n-a-Si: H) layer is grown through a plasma-enhanced chemical vapor deposition (PECVD) process. Subsequently, it is annealed at 900 ºC to convert it into an nPoly-Si layer.

Manufacture of P-type substrate: Silicon oxide (SiOx) or silicon nitride (SiNx), along with other materials, is employed to manufacture the P-type substrate as support for the next step of n-a-Si layer growth.

Growth of P-type layer: A high-quality n-a-Si layer, approximately 100-200 nm thick, is grown on the P-type substrate using an oxidation reduction method.

Fabrication of M Face: An electrochemical deposition process is used to create a metallic aluminum (Al) coating on the n-a-Si layer, serving as the front metal contact surface for the TOPCon cell.

Manufacture of Topcon cell back: Materials like water oxide (H2O) or hydroxide (OH) are applied to the back of the cell to form a transparent conductive film by applying voltage.

Passivation: Wet chemistry is employed to form a passive film on the back of the TOPCon cell, enhancing the solar cell’s cycle life.

Separation: The TOPCon cells undergo separation from the substrate, followed by thorough detection and sorting.