This title appears in the Scientific Report :
1999
Please use the identifier:
http://hdl.handle.net/2128/20468 in citations.
Optoelektronisches Verhalten von Dünnschichtbauelementen aus amorphem und mikrokristallinem Silizium
Optoelektronisches Verhalten von Dünnschichtbauelementen aus amorphem und mikrokristallinem Silizium
Aim of this work was a detailed investigation of the optoelectronic properties of pin thin film devices based on amorphous and microcrystalline silicon for photovoltaic and sensor application. The influence of the spatial distribution as well as the charge state of the defect states within the i-lay...
Saved in:
Personal Name(s): | Zimmer, J. (Corresponding auhtor) |
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Contributing Institute: |
Institut für Schicht- und Ionentechnik; ISI |
Imprint: |
Jülich
Forschungszentrum, Zentralbibliothek
1999
|
Dissertation Note: |
München, Techn. Univ., Diss., 1999 |
Document Type: |
Book Dissertation / PhD Thesis |
Research Program: |
ohne FE |
Series Title: |
Berichte des Forschungszentrums Jülich
3683 |
Subject (ZB): | |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
Aim of this work was a detailed investigation of the optoelectronic properties of pin thin film devices based on amorphous and microcrystalline silicon for photovoltaic and sensor application. The influence of the spatial distribution as well as the charge state of the defect states within the i-layer on the device performance is demonstrated and explained by means of the temperature and illumination level dependence of the solar cell behavior. Thereby numerical simulations are compared with experimental results and show a good agreement. The gained knowledge is transferred on the investigation of new absorber materials like amorphous silicon-germanium alloys (a-SiGe:H) and microcrystalline silicon (uc-Si.H), The application of a-SiGe:H as a material for the absorption layer offers the possibility for a variation of the band gap as a function of depth. Besides the optical properties also the electronic behavior differs significantly with varying band gap grading. A comparison of the experimentally observed current-voltage (IN) behavior with simulated data reveals crucial differences in the spatial distribution of the defect states as a function of the band gap design. Therefore, the transport and recombination behavior varies significantly. The device modeling enabled the development of a band gap design that shows a better extraction of photo generated carriers and a lower sensitivity with regard to light induced degradation. The theoretical prediction was confirmed in the experiment. Due to its electronic properties aSiGe: H is also suitable for sensor application. By comparison of the experimental and simulated bias voltage and bias illumination dependent collection efficiency the operation principle of a color sensitive p-i-i-i-n structure with a specially designed band gap profile is discussed. Furthermore, the optoelectronic behavior of laterally-structured a-SiGe:H pin solar cells showing a lateral modulation of the thickness of the front contact layer is investigated by two-dimensional simulations. The modeling results reveal a laterally inhomogeneous distribution of the carrier generation and electric field strength, giving rise to advantageous optoelectronic properties. Moreover, the transport and recombination behavior of pin solar cells with a microcrystalline (uc-Si.H) absorption layer is investigated. A comparison of simulated and experimentally determined data (dark and illuminated I1V-behavior, bias voltage and bias light dependent quantum efficiency) suggests a microstructure of the uc-Si.H material consisting of (perfect) crystalline grains surrounded by defect rich grain boundaries. Amorphous phase can be distributed between the crystalline columns or arranged in clusters within the material without having a significant influence on the electronic transport. |