Photovoltaic Technology

PENGARANG : A.Shah,  P.Torres, R.Tscharner, N.Wyrsch, H.Keppner

PENERBIT  : IEEE

JUDUL         : Photovoltaic Technology: The Case  for Thin-Film Solar  Cells

Photovoltaic Technology: The Case  for Thin-Film Solar  Cells

The photovoltaic (PV) effect was discovered in 1839 by Edmond Becquerel. For a long time  it  remained  a  scientific  phenomenon with few device applications. After the intro- duction of silicon as the prime semiconductor material in the late 1950s, silicon PV diodes became available. They were soon indispens- able for supplying electrical power to tele- communications equipment in remote loca- tions and to satellites. Then, in the 1970s, a major reorientation took place in the general perception of the energy supply problem: The oil crisis of 1973 led to a general public awareness of the limitation of fossil fuels; many governments (including those of the United States, Japan, and several European countries) started, a few years later, ambitious programs in the search for alternative energy sources, including PV solar energy. This trend was reinforced

The advantages  and  limitations  of pho- tovoltaic  solar modules for energy gene- ration  are reviewed with their operation principles and  physical efficiency limits. Although  the  main  materials   currently used  or investigated  and the  associated fabrication technologies are individually described, emphasis is on silicon-based solar  cells. Wafer-based  crystalline  sili- con solar modules dominate  in terms  of production,  but  amorphous  silicon solar cells have the potential  to undercut costs owing, for example, to the roll-to-roll production possibilities for modules. Recent develop-ments  suggest that  thin- film crystalline  silicon (especially micro- crystalline  silicon) is becoming  a  prime candidate for future photovoltaics.

Charge separation. In the second step of the energy conversion process, the photoge- nerated  electron-hole  pairs  are  separated, with electrons drifting to one of the elec- trodes and holes drifting to the other elec- trode, because of the internal electric field created by the diode structure of the solar cell. The dark (nonilluminated) characteris- tics of the diode and the photogenerated current  can in principle, be linearly super

Crystalline silicon solar cells: The trend to- ward thin-film crystalline silicon. As .80% of solar cells produced at present are crystal- line silicon solar cells (6 ) and the remaining 20% are mostly amorphous silicon solar cells (which are mainly restricted to consumer electronics), almost all PV systems with .1- kW peak power rating (kWp ) are fitted with crystalline  silicon  solar  cells.  These  solar cells were until very recently exclusively based on the use of silicon wafers. Alterna- tive structures, such as silicon ribbons, are just being introduced into the market.

figur 1. (A) Electrical equivalent  circuit of a PV solar cell (61). The diode is a dark (nonillumi- nated) p-n or p–i-n diode. Additional recombina- tion (particularly in the i-type layer of p–i-n di- odes) is represented by the current source, which counteracts  the photogenerated current. Rs  and Rsh  are resistors that  represent  electrical losses (for example, Rs losses due to contact resistance and Rsh  losses due to pinholes through the solar cell). (B) Typical I-V characteristics of a solar cell,with the  three  characteristic  parameters:  short- circuit current Isc, open-circuit voltage Voc, and fill factor FF 5 Pmax /(Voc  3 Isc ); Pmax  is the electrical power  delivered by  the  cell at  the  maximum power point.

Strength:    pembangkit listrik menggunakan ftovoltaic merupakan energi alternatif yang sangat baik apalagi digunakan diindonesia yang sangat kaya sinar matahari sepanjang tahun tanpa adanya musim dingin dan musim lain yang minim sinar matahari.

Weakness: biaya pemasangan pertama yang mahal sehingga orang indonesia kurang tertarik dengan sumberdaya alternatif ini.