Decoupling of optoelectronic properties from morphological changes in sodium treated kesterite thin film solar cells
| Autor: | Melanie Bürki, Yaroslav E. Romanyuk, Claudia Schreiner, Raquel Caballero, Romain Carron, Ayodhya N. Tiwari, Torsten Schwarz, Stefan G. Haass, Renato Figi, Thomas Paul Weiss, Christian Andres |
|---|---|
| Přispěvatelé: | UAM. Departamento de Física Aplicada |
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Sodium chemistry.chemical_element 02 engineering and technology Atom probe engineering.material 01 natural sciences law.invention Kesterite X-ray photoelectron spectroscopy law 0103 physical sciences General Materials Science Thin film 010302 applied physics Sodium doping Renewable Energy Sustainability and the Environment Open-circuit voltage Física Thin films solar cells 021001 nanoscience & nanotechnology Grain growth chemistry Chemical engineering engineering Grain boundary 0210 nano-technology Rapid thermal processing |
| Zdroj: | Biblos-e Archivo. Repositorio Institucional de la UAM instname |
| ISSN: | 0038-092X |
| Popis: | Sodium is typically used during the synthesis of kesterite thin films to enhance the performance of solar cells. As sodium tends to affect grain growth and morphology, it is difficult to analyse solely the electronic effects of sodium as dopant. To decouple the structural and electronic effects from each other, two processes were designed in this work to successfully incorporate sodium into a vacuum-processed Cu2ZnSnSe4absorber without changing the morphology. A thin layer of NaF is deposited before precursor deposition (Pre-NaF) or after absorber synthesis to undergo a post deposition treatment (NaF-PDT). While composition and distribution of matrix elements remain unchanged, the sodium concentration is increased upon sodium treatment up to 140 ppm as measured by inductively coupled plasma mass spectrometry. X-ray photoelectron spectroscopy showed that the surface composition was not altered. Within its detection limit, sodium was not present at the absorber surface. For a Pre-NaF sample measured with atom probe tomography a sodium concentration of 30 ppm was measured in a grain, suggesting that sodium might segregate at grain boundaries. The additional sodium content in the film leads to an increased acceptor concentration, which results in improved open-circuit voltage and fill factor. Financial support from the Swiss National Science Foundation (SNF) in the network of the Indo-Swiss Joint Research Programme (ISJRP) [IZLIZ2_157140/1] is gratefully acknowledged. T. Schwarz is grateful for the support of the German Research Foundation (DFG) [Contract GA 2450/1-1]. R. Caballero acknowledges financial support from Spanish MINECO within the Ramón y Cajal program [RYC-2011-08521], MINECO project WINCOST [ENE2016-80788-C5-2-R] and from Spanish Ministry of Education, Culture and Sport within the José Castillejo program [CAS 15/00070] |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect