High-rate deposition of epitaxial layers for efficient low-temperature thin film epitaxial silicon solar cells

2001 ◽  
Vol 9 (5) ◽  
pp. 333-340 ◽  
Author(s):  
Lars Oberbeck ◽  
Jan Schmidt ◽  
Thomas A. Wagner ◽  
Ralf B. Bergmann
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Low Temperature ◽  
High Rate ◽  
Silicon Solar Cells ◽  
Epitaxial Layers ◽  
Epitaxial Silicon

Plasma Texturing and Porous Silicon Mirrors for Epitaxial Thin Film Crystalline Silicon Solar Cells

2008 ◽  
Vol 1101 ◽  
Author(s):  
Izabela Jozefa Kuzma-Filipek ◽  
Filip Duerinckx ◽  
Kris Van Nieuwenhuysen ◽  
Guy Beaucarne ◽  
Jef Poortmans
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Porous Silicon ◽  
Crystalline Silicon ◽  
Internal Reflection ◽  
Electrochemical Anodization ◽  
Silicon Solar Cells ◽  
Textured Surface ◽  
Epitaxial Silicon ◽  
Substrate Interface

AbstractThin film silicon solar cells, consisting of an epitaxially grown active layer on a low quality highly doped silicon substrate, incorporate many attractive features usually associated with their sister cells based on bulk silicon. However, the efficiency of the current epitaxial semi-industrial screen printed cells is limited to 11-12% mainly due to optical shortcomings. This paper will give an overview of our work aimed at tackling the 2 most important problems: (i) Finding and implementing an adequate front surface texture and (ii) the simulation, fabrication and incorporation of an intermediate reflector.The former issue has been addressed by the development of plasma texturing based on halogen species. This method allows us to fulfil the sometimes contradictory requirements for the textured surface, i.e. a uniform and reduced reflection, a strong lambertian character to scatter the light and a limited removal of silicon. It will be shown that the scattering efficiency is dependent on both the wavelength of the impinging light and on the silicon removal during the texturing process.The second and main issue of this work is the limited absorption volume of the epitaxial layer. To resolve this drawback, an intermediate reflector is placed at the epi/substrate interface to enhance the path length of the low energy photons through the epi-layer. In practice, a multi-layer porous silicon stack is created by electrochemical anodization of the substrate. The reflection at the epi/reflector/substrate interface is a combination of several different effects including a Bragg mirror and Total Internal Reflection (TIR). Measurements of the external reflectance as well as extraction of the internal reflection parameters are used to clarify the issue. Advanced structures, including chirped porous silicon stacks, are introduced. Finally, the benefits of the reflector on the level of the epitaxial silicon solar cell are analysed. Efficiencies close to 14% are obtained for epitaxial cells incorporating an advanced porous Si reflector.

A porous silicon intermediate reflector in thin film epitaxial silicon solar cells as a gettering site of impurities

2009 ◽  
Vol 6 (7) ◽  
pp. 1745-1749 ◽  
Author(s):  
Izabela Kuzma-Filipek ◽  
Filip Duerinckx ◽  
Kris Van Nieuwenhuysen ◽  
Guy Beaucarne ◽  
Jef Poortmans ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Porous Silicon ◽  
Silicon Solar Cells ◽  
Epitaxial Silicon

High-Rate Deposition of Intrinsic a-Si:H and μc-Si:H Layers for Thin‑Film Silicon Solar Cells using a Dynamic Deposition Process

2012 ◽  
Vol 1426 ◽  
pp. 27-32
Author(s):  
T. Zimmermann ◽  
A. J. Flikweert ◽  
T. Merdzhanova ◽  
J. Woerdenweber ◽  
A. Gordijn ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Chemical Vapor ◽  
Deposition Process ◽  
High Rate ◽  
Silicon Solar Cells ◽  
Plasma Sources ◽  
Thin Film Silicon ◽  
Very High ◽  
Linear Plasma

ABSTRACTThin‑film silicon solar cells based on hydrogenated amorphous silicon (a‑Si:H) and hydrogenated microcrystalline silicon (μc‑Si:H) absorber layers are typically deposited using static plasma-enhanced chemical vapor deposition (PECVD) processes. It has been found that the use of very‑high frequencies (VHF) is beneficial for the material quality at high deposition rates when compared to radio-frequency (RF) processes. In the present work a dynamic VHF‑PECVD technique using linear plasma sources is developed. The linear plasma sources facilitate the use of very-high excitation frequencies on large electrode areas without compromising on the homogeneity of the deposition process. It is shown that state-of-the-art a‑Si:H and μc‑Si:H single-junction solar cells can be deposited incorporating intrinsic layers grown dynamically by VHF-PECVD at 0.35 nm/s and 0.95 nm/s, respectively.

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