SOFTPV’s SOFTCELL® technology consists of manufacturing silicon balls, forming electrodes, and mounting SOFTCELL® onto SOFTFORM® to create SOFTGOODS®, the final activated module.
The ground polysilicon powder is placed in a high-temperature oven, melted, and cooled to produce silicon balls with a predetermined size by meticulously controlling the crystallization. After ball-shaped, they were treated to form the PN junction, one of the main semiconductor characteristics. Additional various and functional layers on the surface of silicon balls are fabricated to reach optimum efficiency to generate power under general lighting conditions.
A. Ball Manufacturing
The manufacturing of the silicon balls with diameter 0.35~ 1.8mm
- Prepare the Boron doped silicon ingot Top/Tail as base material
- Crush and grind them into size ~100 µm
- Crystallize them by melting over 1300 degrees Celsius and cooling down slowly
- Polish the crystallized silicon particles to perfect spherical shape in designed size
[The conceptual view of forming silicon balls using a flat jig]
B. Functional Multilayer Fabrication
Treatments of the silicon ball to have PN junction semiconductor characteristics
- Form the N-type semiconductor layer by coating POCl3 and diffusing it. After the diffusion of several hundreds of nm, the silicon balls can hold PN junction semiconductor characteristics
- Apply the passivation layer to minimize photoelectron loss when required
- Create the anti-reflection layer to maximize light absorption.
- Build the transparent conductive oxide layer to efficiently extract photoelectron
[Schematic views of fabricating functional layers]