Intrinsic microcrystalline silicon A new material for photovoltaics:Intrinsic microcrystalline silicon A new material for photovoltaics
Abstract
Microcrystalline silicon (lc-Si :H) prepared by plasma-enhanced chemical vapor deposition
(PECVD) has been investigated as material for absorber layers in solar cells. The deposition
process has been adjusted to achieve high deposition rates and optimized solar cell performance.
In particular, already moderate variations of the crystalline vs. amorphous volume
fractions were found to e!ect the electronic material } and solar cell properties. Such variation
is readily achieved by changing the process gas mixture of silane to hydrogen. Best cell
performance was found for material near the transition to the amorphous growth regime. With
this optimized material e$ciencies of 7.5% for a 2 lm thick lc-Si :H single solar cell and 12%
for an a-Si :H/lc-Si :H stacked solar cell have been achieved. ( 2000 Elsevier Science B.V. All
rights reserved.
Keywords: Microcrystalline silicon; Solar cells; Deposition rate