Onno, A;
Tang, M;
Oberbeck, L;
Wu, J;
Liu, H;
(2017)
Impact of the growth temperature on the performance of 1.70-eV Al 0.22 Ga 0.78 As solar cells grown by MBE.
Journal of Crystal Growth
, 475
pp. 322-327.
10.1016/j.jcrysgro.2017.07.011.
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Abstract
Growth of high material quality Aluminum Gallium Arsenide (AlxGa1-xAs) is known to be challenging, in particular with an Al content x above 20%. As a result, the use of AlxGa1-xAs in devices requiring high minority carrier lifetimes, such as solar cells, has been limited. Nonetheless, it has long been established that the substrate temperature is a key parameter in improving AlxGa1-xAs material quality. In order to optimize the growth temperature of 1.70-eV Al0.22Ga0.78As solar cells, five samples have been grown by Solid-Source Molecular Beam Epitaxy (SSMBE) at 580 °C, 600 °C, 620 °C, 640 °C, and 660 °C, respectively. A strong improvement in performance is observed with increasing the growth temperature from 580 °C to 620 °C. An open-circuit voltage above 1.21 V has in particular been demonstrated on the sample grown at 620 °C, translating into a bandgap-voltage offset Woc below 0.5 V. Above 620 °C, performances – in particular the short-circuit current density – moderately decrease. This trend is confirmed by photoluminescence, current density versus voltage characterization under illumination, and external quantum efficiency measurements.
| Type: | Article |
|---|---|
| Title: | Impact of the growth temperature on the performance of 1.70-eV Al 0.22 Ga 0.78 As solar cells grown by MBE |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.jcrysgro.2017.07.011 |
| Publisher version: | http://doi.org/10.1016/j.jcrysgro.2017.07.011 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | B2. Aluminum Gallium Arsenide; B3. Solar cells; A3. Molecular Beam Epitaxy; A3. Growth temperature |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Electronic and Electrical Eng |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1565499 |
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