Black Silicon Enhanced Thin-Film Silicon Photovoltaic Devices

Picture of a thin film black silicon photovoltaic cell. The black silicon regions are the two dark rectangular regions on the right image. On the left is a backside view showing the metal contacts on the surface of the black silicon.

An enhanced thin-film silicon photovoltaic device with improved efficiency has been developed. Thin-film silicon solar cells suffer from low material absorption characteristics, resulting in poor cell efficiencies. SiOnyx’s approach leverages black silicon, an advanced material fabricated using ultra-fast lasers.

The laser-treated films show dramatic enhancement in optical absorption with measured values in excess of 90% in the visible spectrum and well over 50% in the near infrared spectrum.

Thin-film black silicon solar cells demonstrate 25% higher current generation with almost no impact on open circuit voltage as compared with representative control samples. The initial prototypes demonstrated an improvement of nearly 2 percentage points in the suns Voc efficiency measurement. In addition, the researchers validated the capability to scale this processing technology to the through-puts (< 5 min/m²) required for volume production using state of the art commercially available high power industrial lasers. With these results, the feasibility for the enhancement of thin-film solar cells with this laser processing technique was clearly demonstrated.

This work was done by SiOnyx and provided the necessary feasibility to secure a development program to support thin film flexible photovoltaics for soldier applications funded by DARPA.