Finnish company, Picosun Oy, reports in a Jan. 2, 2012 news item on Nanowerk about a successful research project on solar cells undertaken as part of the European Union 7th Framework Programme. From the news item on Nanowerk,
… The goal of this multinational, inter-European, three years (2009-2011) project combining the efforts of both scientific and industrial partners has been to dramatically increase the efficiency of solar cells and reduce the costs of their manufacturing. This has been achieved with novel, innovative, silicon nanorod based concept. The amount of active photovoltaic material (Si) can be significantly reduced by growing the light-trapping nanorod “forests” (thickness from < 1µm to a few µm at most) on cheaper substrates such as glass or flexible foils. …
An ultrathin ALD-deposited Al2O3 film serves ideally this purpose, and the gas-phase, surface-controlled and self-limiting nature of the ALD process ensures that even the deepest and narrowest between-the-rods nooks and crannies will be reliably covered with 100 % uniform, conformal and pinhole- and defect-free passivation film. Another central cell component where ALD has shown its indispensability is the transparent conductive oxide (TCO) layer that works as the current collector on the top of the cell. Different TCO deposition methods were investigated in the course of the project, and ALD turned out to be the ideal method regarding both the TCO film quality and the scalability of the technique, due to Picosun’s fast, efficient and easy-to-use HVM (High Volume Manufacturing) batch ALD system, which was developed specifically during the project ROD-SOL.
“Solar photovoltaics still remains one of the fastest growing industries in the world. To enable more efficient utilization of this free, clean energy, the efficiencies of the solar cells have to increase and their manufacturing costs decrease. ROD-SOL’s silicon nanorod cell concept shows promising potential to this, and we at Picosun have been especially satisfied of the ALD’s central role in realizing this novel, innovative, high efficiency solar electricity converter”, states Picosun’s Managing Director Juhana Kostamo.
More technical details are available in the news item on Nanowerk. I last wrote about Picosun Oy in a July 11, 2011 posting about a collaboration between the company and Carleton University researchers Sean Barry and Jason Coyle on a technique for plasma-enhanced atomic layer deposition.