Printed Photovoltaics: Market Opportunities for the Materials and PV Industry

Printing has always had a role in photovoltaics: the top electrodes for conventional crystalline silicon PV are inevitably screened silver. However, the opportunities for using printing technology in the PV industry has expanded enormously in the past few years and now includes not just the printing of electrodes, but of the core PV absorber layer itself, which is increasingly a thin-film material and thus printable.

From the PV side of the house, firms have been driven to consider and use printing technology in the belief that R2R printing technologies will reduce the cost of manufacturing compared with the more usual PVD approaches to manufacturing. In addition, printing technologies also seem well suited to the plastic substrates and organic PV materials that are now being developed and deployed in the PV industry. On the other hand, from the perspective of functional printing, PV represents a growth market in an era in which many of the other market sectors that were supposed to drive printed electronics have gone dry. Printed PV is, however, a business with its own unique issues; printing PV tends to reduce conversion, efficiencies.

In this report, NanoMarkets identifies and quantifies the markets and opportunities for printed PV. It discusses both the printing of electrodes and the absorber layer for silicon, CdTe, CIGS, organic (OPV) and dye sensitive cell (DSC) PV. This report identifies the types of printing being developed for each of the TFPV materials and discusses the impact this will have for materials and equipment suppliers. Where appropriate, short profiles of key firms are provided. Finally, eight-year forecasts are provided for each of the printed PV technologies.

Chapter One: Introduction

1.1 Background to This Report

Printing is not a new concept for the photovoltaics (PV) industry; in fact, it has relied on screen printing to create the top electrodes for crystalline silicon (c-Si) PV for some time. This is a somewhat unexciting application, but one that accounts for almost $200 million in sales of silver inks and pastes. In addition, this means that the PV industry is at least familiar with functional printing and what it can deliver.

An obvious next step is to use functional printing to create the core PV layer itself. The reason why a solar cell firm would want to do this is primarily one of cost. Although PV producers might be loath to admit it, at any given efficiency level, their products are something of a commodity. There really isn't that much to choose between one brand and another other than price. This is one reason why panel makers build the factories close to key geographical markets; solar panels are heavy and transportation can add considerably to costs. So making the right production location decision can be critical.

So can choosing the right manufacturing technology and--in theory at least--printing seems to fit in quite well in this regard. Not only is it an approach that is well understood in the PV industry, but printing is generally considered a low cost approach compared with other deposition technologies that are taken from the semiconductor industry. This is true at the level of capital expenditure and operational expenditure. As far as the latter is concerned, printing supposedly reduces the amount of energy and material consumed in the manufacture of solar cells compared with other more traditional deposition approaches. This is obviously important intrinsically, but also helps preserve the image of PV as a "green technology." In addition, printing is uniquely a deposition and a patterning technology. This may be important for texturing electrodes (or sometimes even the absorber layer), which translates directly into higher performance cells.

Finally, printing has the advantage that it is very well suited to flexible substrates and this in turn means that it is a good choice for building integrated PV (BIPV) products; these value-added products are yet another way that PV companies can distinguish their products in the marketplace.

This is the theory anyway. The reality is a little different. For a start, using printing, as opposed to a high-temperature manufacturing processes, usually leads to a substantial reduction in performance in the final cell, and this is only partially offset by the fact that one process can be used for deposition and texturing. Since performance (i.e, energy conversion efficiency) is the key measure of the usefulness of a cell, this is a big limitation. In addition, casual descriptions of printing PV make it sound like all one can merely buy a screen printing machine or industrial inkjet and be up and running printing PV in a month or so. The reality is that printing PV can be very difficult technically, with lots of operational problems standing between the inception of an idea and it realization. This is a fact that many in the PV industry seem blissfully unaware of.

With all that said, printed PV definitely seems like an opportunity for the printed electronics (PE)/functional printing community, which seems to have floundered somewhat in the past year. First this community has never been able to keep up with some of its more extravagant promises from its early years. Second, it has been hit hard by the worldwide economic downturn. What PV represents is a remaining addressable market where printing can be applied and which is still in growth mode, although at lower rates than were expected a year or so back. This has caused a repositioning in the PE industry. For example, several conductive silver ink makers are now specifically rebranding their inks and pastes for the PV market and at least one PE start up that was focusing on printed transistors just a few months back is now a PV company!