Tandem self-powered photovoltaic-electrochromic window coatings
- National Renewable Energy Lab., Golden, CO (United States)
Wide-gap, transparent amorphous silicon based photovoltaics can be integrated with electrochromic materials to produce a self-powered ``smart`` window coating. Existing electrochromic window designs external electrical connection, which may be economically unfeasible. This problem is solved by the tandem photovoltaic-electrochromic (PV/EC) device, in which a wide-gap amorphous silicon-based alloy (a-SiC:H) photovoltaic device is deposited together with an electrochromic optical transmittance modulator in a monolithic device on a single substrate. In this paper, the authors discuss their proposed monolithic photovoltaic-electrochromic device. They also present studies of transparent, wide-gap (Tauc gap of 1.8 to 2.2 eV) amorphous silicon-carbon thin films and p-i-n devices designed for use in the photovoltaic-electrochromic device. The photovoltaic cells in the PV-EC can operate at low current (<1 mA/cm{sup 2}) because a total injected charge of only 60 {micro}C/cm{sup 2} will darken the EC layer to a visible transmission of 5%, but they will need a high open-circuit voltage (>1.0 V) and high transparency ({approx}70%). They describe the progress toward these design targets.
- DOE Contract Number:
- AC36-83CH10093
- OSTI ID:
- 197602
- Report Number(s):
- CONF-950793--; ISBN 0-8194-1890-0
- Country of Publication:
- United States
- Language:
- English
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