The solar cell family is mainly composed of two categories: crystalline silicon cells and amorphous silicon cells. Compared with crystalline silicon solar cells, amorphous silicon solar cells, including silicon-based thin-film solar cells, have outstanding advantages such as large volume for daylighting, low production cost, and good low-light power generation.
Thin-film solar cells are the second-generation solar cell technology, and are currently the most important photovoltaic cell types along with the first-generation crystalline silicon cells. It is made by attaching a photosensitive material with a thickness of only a few microns on an inexpensive glass, stainless steel or plastic substrate. , And it uses less material, light weight, smooth appearance, easy installation, and has the characteristics of strong low light application. It can not only generate electricity, beautify the environment, but also replace building materials, and has a wide range of applications.
Of course, thin-film solar cells also have shortcomings, that is, the conversion efficiency is relatively low under the current technical conditions, only 8.2% in 2006, and increased to 12% in 2007. Among silicon-based solar cells, the conversion efficiency of polycrystalline silicon cells with low conversion efficiency can reach 13% to 16% in the commercial field, and the conversion efficiency of monocrystalline silicon cells can reach 15% to 18%. However, under the current situation that the supply of silicon materials in the upstream of the photovoltaic industry chain continues to be tight, many photovoltaic cell manufacturers have increased their investment in the research and development of thin-film solar cells, which will further improve the conversion efficiency of thin-film solar cells in the future. Due to the cost advantage of large-scale production of batteries, its market share is expected to further increase. According to the previous forecast of the European Energy Association, thin-film solar cells will occupy 20% of the photovoltaic market by 2010.
As early as the 1970s, amorphous silicon thin films were developed, but because the conversion efficiency is only half that of polysilicon, it has not been popularized. The skyrocketing price of silicon raw materials has made thin-film batteries resurface.
Thin-film photovoltaics accounted for 12% of total photovoltaics in 2007, mainly entering the growing grid-connected market. In 2008, Applied Materials and Oer1ikon became competitors in a new market for thin-film photovoltaic manufacturing equipment. Although the conversion efficiency of thin-film photovoltaic modules is lower, their prices are lower than that of crystalline silicon, which is only above $4/W p.
Figure 1 shows the contribution of thin-film photovoltaic technology to the sales and demand of the entire photovoltaic industry from 1980 to 2007. Thin-film technology developed strongly in the mid-1980s and peaked in the late 1980s thanks to increased demand for indoor applications such as calculators.
By 2007, the output of thin-film batteries has increased by 120% compared with 191MW in 2006, and its market share has increased from 8.2% in 2006 to 12%. Table 1 lists the growth of thin-film battery production in the world from 2001 to 2007. According to forecasts, photovoltaic cells will grow at an annual rate of more than 55% by 2015. Among them, the growth rate of crystalline silicon will exceed 50%, while the thin film battery will grow at an annual rate of 75%. Among the total output of 3436MW in the world, the two commercial solar cells, crystalline silicon cells and thin-film cells, have the largest contribution.
In 2008, the global output of thin-film solar cells reached 892MW, a year-on-year increase of 123%. In 2007, the global output of thin-film solar cells reached 400MW, an increase of 110% from 191MW in 2006. The output growth rate has exceeded 120% for two consecutive years, showing the extremely strong development momentum of thin-film solar cells.
As of July 2009, single-product silicon, multi-product silicon, and thin-film solar cells have emerged as new solar energy technologies on the market. Thin-film has occupied 7% to 10% of the photovoltaic market. According to the Prometheus Institute for Sustainable Development, headquartered in Massachusetts, by 2012, non-silicon thin-film applications will account for 25% of the market.
In terms of production technology, it has become the future development trend of traditional crystalline silicon photovoltaics to thin film photovoltaics. In mid-August 2009, the European strategic consulting firm Roland Berger pointed out that the thin-film photovoltaic market share in 2007 was less than 10%, but it is expected to account for 25% of the market share of new installations by 2013, and will reach 25% in 2030. 35%. The thin film market will grow at a double-digit annual rate, increasing its share. The capacity building of some well-known companies has formed a strong support for this growth. Japan’s Sharp, Showa and China’s PepsiCo have announced that they will build more than 1GW of thin-film photovoltaic equipment and put them into operation in 2010.
According to a report on photovoltaic cell capability database and development trend released by American Display Search Company, which is engaged in research, in 2005, 95% of solar cell production capacity was crystalline silicon solar cells, and 5% was thin-film solar cells. By the end of 2009, thin-film solar cells accounted for more than 20% of solar cell capacity, and by 2013, thin-film technology is expected to account for 30% of solar cell capacity.
Na no Markets released an analysis and forecast report on July 9, 2008, that the thin-film photovoltaic market will exceed 26GW by 2015, and the operating income will exceed 20 billion US dollars during this time period. The extremely fast growth rate is partly due to the rapid growth of all types of photovoltaics, but also due to the advantages associated with low cost, flexibility and manufacturing of TFPV compared to the now dominant crystalline silicon PV. Na no Markets predicts that by 2015, thin-film photovoltaics will account for more than half of the world’s PV production.
Na no Markets’ analysis predicts that:
(1) The recent success of cadmium telluride solar cells will continue to grow and will be the largest segment of the TFPV market by 2015, with a turnover of $8.7 billion in this active material market. Diluted cadmium has many advantages, such as high light absorption coefficient, as well as environmental advantages.
(2) Despite higher prices and obvious manufacturing challenges, CIS/CIGS is still the star of the TFPV world. Technological developments will accelerate the full benefits of combining thin films with higher conversion efficiencies. The CIS/CIGS segment is said to generate nearly $5 billion in operating income by 2015.
(3) TFPV is highly recommended for residential sector more than conventional PV due to its low cost, low weight, and ability to be assembled on flexible substrates. It is said that by 2015, it will occupy a market of 2.3 billion US dollars in the residential TFPV market.
The technical problems of developing thin-film photovoltaics also pose challenges to the chemical industry, for example, improvement of the deposition process of absorber layers (speed, quality, thickness), avoidance of moisture intrusion (especially in their flexibility applications), innovative transparent conductive oxides improvements in the packaging design of objects or conventional modules, etc. This requires manufacturers to improve existing materials, or to introduce and develop new products.
Roland Berger, a European strategic consulting company, pointed out that with the rapid growth of the photovoltaic industry, the continuous expansion of the share of thin-film photovoltaics and the increase in the amount of chemicals used in thin-film photovoltaics, it is expected that the potential market size of crystalline silicon and thin-film in photovoltaic chemicals will reach 2030 respectively. 3.5 billion euros and 7.4 billion euros, much higher than the 2007 market expectations of 260 million euros and 100 million euros.
Figure 2 shows the changes in the market share of thin-film photovoltaics and crystalline silicon photovoltaics in the solar panel market from 2008 to 2013.
First Solar has established a leading position in the production of thin film photovoltaic solar cells, becoming the world’s top producer in 2009 with a production capacity of over 1GW. The company’s production cost has been less than 90 cents/W. It is half of the production cost of crystalline silicon modules.
Another driving force for the development of thin film technology is the continuous improvement of production lines, typical companies are Applied Materials, Oer1ikon and Centrotherm.
The 2020 Vision Forecast Report released by the European Photovoltaic Industry Association (EPIA) on November 28, 2009 believes that thin film technology is expected to account for 1/3 of the total PV market by 2020. Thin film technology has many advantages, such as Low cost (developed for improved building integration), high material applicability, high flexibility and low environmental carbon footprint, energy payback periods of less than one year for some thin-film technologies (at best settings can be as low as half a year), The payback period is expected to decrease further as manufacturing processes improve and material applications decrease.
Research and information provider Na no Markets released a thin-film PV material forecast report on December 22, 2009, arguing that the thin-film PV material market will increase to $13.1 billion in 2017. Following the low ebb in 2009, Na no Markets predicts that the thin-film photovoltaic industry will recover in 2010, which will provide development opportunities for various materials companies. Na no Markets believes that a new class of encapsulation materials is now opening up the flexible BIPV market for CIGS and Cd Te. The most interesting is the polymer/ceramic paired film launched by Foot Chemical Company, Fuji Thin Film Company (Fuji Zhengi1m), DuPont Company and 3M Company in 2009. By 2017, the sales of TFPV packaging materials are expected to reach 1.6 billion. Dollar.