UNSW Sydney has received a funding grant from ARENA to investigate and optimise the compatibility of emerging high-throughput black silicon texturing techniques with existing and next-generation solar cell production processes.
The Integrating Industrial Black Silicon project will work towards reducing the costs of solar cell modules by enabling lower cost and less wasteful wafer fabrication methods and by improving anti-reflection and light-trapping properties of multicrystalline silicon solar cells.
Researchers at UNSW developed advanced characterization techniques to measure complex black silicon surface morphologies. These techniques have allowed for a greater understanding of the fundamental nature of black silicon and its interaction with solar cell processing steps.
The project created and validated new modelling techniques that allow the optical performance of black silicon textures to be rapidly predicted. These models have been integrated with widely available software enabling the annual energy yield of black silicon textured devices to be determined within minutes (rather than many hours with incumbent modelling techniques).
Together with its industry partner Canadian Solar, this project successfully demonstrated the integration of industrial black silicon textures into stable, high efficiency solar cells. Fundamental studies showed the solar cell processing modifications needed to achieve high performance and provided insights into the suppression of degradation losses.
Report: Integrating Industrial Black Silicon with High Efficiency Multicrystalline Solar Cells Lessons Learnt
This is the final report that discusses the project results and lessons learnt to date for the UNSW Project, Integrating Industrial Black Silicon with High Efficiency Multicrystalline Solar Cells.
How the project works
Silicon solar modules continue to dominate the photovoltaic market, and whilst numerous technological developments have led to a steady lowering of costs and increase in efficiency over the years, there is still potential for further improvements. A significant portion of current module fabrication costs is attributed to the raw silicon wafers. To reduce these costs, much of the industry has now moved towards diamond wire sawing which results in more economical wafer production, however, these wafers are not compatible with conventional subsequent texturing processes for multicrystalline silicon solar cells. Alternative texturing solutions for this material are therefore now being sought out by industry.
UNSW researchers will work closely with major solar industry partners specialising in both silicon wafer and solar module production to investigate and optimise the leading approaches to multicrystalline silicon texturing, referred to by industry as ‘black silicon’. The project partners will supply UNSW with a large range of industrially producible black silicon samples which will then be thoroughly characterised and tested against subsequent state-of- the-art and next generation solar cell device fabrication processes. The project outcomes will lead to broader use of more economical silicon wafers and improvements in multicrystalline solar cell efficiencies through enhanced light-trapping effects.
Area of innovation
Whilst black silicon texturing is a relatively well established technique, its ultimate potential towards improving commercial scale photovoltaics has not yet been gauged. The project will determine the current and future potential of black silicon technology, including its compatibility with patented UNSW developed advanced hydrogenation techniques which have been shown to improve cell efficiencies and stability for current state-of- the-art commercial devices.
The Integrating Industrial Black Silicon project will provide a route towards enabling the use of diamond wire sawn multicrystalline silicon wafers, which are more economical than traditionally produced wafers. Unique optical modelling tools will be developed which will allow for rapid determination of the effect of both nanoscale and microscale surface textures on final module output characteristics. Through simulation and experimental results, black silicon textures and their compatibility with subsequent device fabrication steps will be optimised, leading to lower cost and more efficient solar modules.