| Both sides previous revision
Previous revision
Next revision
|
Previous revision
|
research:absorbers [2011/07/11 22:54]
cxx |
research:absorbers [2013/06/22 20:16] (current)
|
| | ====== Non-conventional Solar Absorbers ====== |
| | Low cost, earth-abundant light absorbers are of great interest for use in terrestrial photovoltaics and in artificial photosynthesis. Non-conventional solar absorbers, e.g., zinc phosphide (Zn<sub>3</sub>P<sub>2</sub>), cuprous oxide (Cu<sub>2</sub>O) and pyrite (FeS<sub>2</sub>), are promising materials for solar energy conversion and have received renewed interests after early work in 1980s. The Lewis group is interested in studying the interface chemistry and fundamental energy-conversion properties of these non-conventional solar absorbers. |
| | ====== Zinc Phosphide ====== |
| | Zinc phosphide is one of the most promising materials for low-cost solar cells. It has a direct bandgap near 1.5 eV, both of its constituent elements are cheap and earth abundant and electron diffusion length in p-type Zn<sub>3</sub>P<sub>2</sub> is relatively long (>10 um). |
| | We have successfully demonstrated synthesis of quasi-single crystal Zn<sub>3</sub>P<sub>2</sub> by physical vapor transport (Figure 1). We are investigating various surface treatment for Zn<sub>3</sub>P<sub>2</sub> to decrease the surface recombination velocity (Figure 2). We are also investigating solar cell performances of Mg/Zn<sub>3</sub>P<sub>2</sub> diodes.\\ |
| | {{:research:absorbers:synthesiszn3p2.png?250x200}}\\ |
| | //Fig. 1. Preparation of quasi-single crystal Zn<sub>3</sub>P<sub>2</sub> substrates.//\\ |
| | {{:research:absorbers:plzn3p2.png?200x200}}\\ |
| | //Fig. 2. Photoluminescence (PL) data demonstrate the improved quality of chemically-treated Zn<sub>3</sub>P<sub>2</sub> surfaces. Time-resolved PL decays show a reduction in surface recombination velocity (SRV) and inset shows enhanced steady-state PL from HF:H<sub>2</sub>O<sub>2</sub> treatment.//\\ |
| | ====== Cuprous Oxide ====== |
| | Cuprous oxide is a native p-type semiconductor, with a bandgap of 2.0 eV and relatively high absorption coefficient in the visible spectrum range. |
| | We are developing synthesis techniques for preparing high quality Cu<sub>2</sub>O substrates (Figure 3). We are using semiconductor/liquid contacts to investigate the energy-conversion properties of prepared substrates (Figure 4). We are also interested in exploring other hetero-junction partners for cuprous oxide substrates.\\ |
| | {{:research:absorbers:synthesis.png?200x160}}\\ |
| | //Fig. 3. Synthesis of Cu<sub>2</sub>O substrates by high temperature thermal oxidation.// |
| | {{:research:absorbers:cu2o.png?200x200}}\\ |
| | //Fig. 4. 820 mV open-circuit voltages were observed from Cu<sub>2</sub>O photoelectrodes in contact with the decamethylcobaltocene<sup>+/0</sup> (Me<sub>10</sub>CoCp<sub>2</sub><sup>+/0</sup>) redox couple. Inset shows an electron diffraction image of the grain structure in Cu<sub>2</sub>O substrates.//\\ |
| | ====== References ====== |
| | - G. M. Kimball, A. M. Muller, N. S. Lewis and H. A. Atwater, "Photoluminescence-based measurements of the energy gap and diffusion length of Zn<sub>3</sub>P<sub>2</sub>",//Appl. Phys. Lett. 95, 112103 (2009).// |
| | - C. Xiang, G. M. Kimball, R. L. Grimm, B. S. Brunschwig, H. A. Atwater, and N. S. Lewis, "820 mV open-circuit voltages from Cu<sub>2</sub>O/CH<sub>3</sub>CN junctions", //Energy Environ. Sci.,4, 1311-1318 (2011).// |
| | \\ |
| |
| | <ifauth @admin,@user> |
| | ==== Uploaded Files ==== |
| | |
| | ++++ Show/hide files in this directory | |
| | {{medialist>@PAGE@}} |
| | ++++ |
| | |
| | <php> |
| | global $ID; |
| | $baseurl = '/lib/exe/mediamanager.php'; |
| | echo '<a href="'.$baseurl.'?ns='.$ID.'" target="_new">Upload or manage files.</a>'; |
| | </php> |
| | </ifauth> |
| | |
| | \\ |
