Effect of synthesis conditions on large and persistent photoconductivity in chemical bath deposited cadmium sulfide thin films
Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | eng |
| Published: |
Massachusetts Institute of Technology
2017
|
| Subjects: | |
| Online Access: | http://hdl.handle.net/1721.1/106772 |
| _version_ | 1811077032778399744 |
|---|---|
| author | Yin, Han, Ph.D. Massachusetts Institute of Technology |
| author2 | Rafael Jaramillo. |
| author_facet | Rafael Jaramillo. Yin, Han, Ph.D. Massachusetts Institute of Technology |
| author_sort | Yin, Han, Ph.D. Massachusetts Institute of Technology |
| collection | MIT |
| description | Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016. |
| first_indexed | 2024-09-23T10:36:40Z |
| format | Thesis |
| id | mit-1721.1/106772 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T10:36:40Z |
| publishDate | 2017 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/1067722020-09-21T18:55:41Z Effect of synthesis conditions on large and persistent photoconductivity in chemical bath deposited cadmium sulfide thin films PPC in CdS thin films Yin, Han, Ph.D. Massachusetts Institute of Technology Rafael Jaramillo. Massachusetts Institute of Technology. Department of Mechanical Engineering. Massachusetts Institute of Technology. Department of Mechanical Engineering Mechanical Engineering. Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016. Cataloged from PDF version of thesis. Includes bibliographical references (pages 60-67). Persistent photoconductivity (PPC) has been observed in numerous semiconductors and dielectrics. It refers to the phenomenon that photoconductivity can last for a long time after photo-excitation is terminated. In most cases, the causes of PPC are unknown, and the connections between synthesis conditions, composition, morphology, and PPC are unexplored. Here, we study the effect of chemical bath deposition parameters on PPC in CdS thin films, including bath temperature, concentration of reactants, deposition time, stirring speed and cation source. By tuning the chemical conditions during deposition, we achieved near stoichiometric CdS thin films exhibiting large photoconductive responses (up to 109 times conductivity increase in simulated solar light compared to the dark) that persist for a long time (decay time constant up to 10 hours) after illumination is turned off. We offer experimental support for the hypothesis that sulfur vacancies are responsible for PPC in CdS, and we discuss the role of trap states in PPC are discussed. We also discuss the implications of giant and persistent photoconductivity for thin film solar cells in which CdS is used as the n-type buffer layer. by Han Yin. S.M. 2017-01-30T19:17:38Z 2017-01-30T19:17:38Z 2016 2016 Thesis http://hdl.handle.net/1721.1/106772 969904913 eng MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission. http://dspace.mit.edu/handle/1721.1/7582 67 pages application/pdf Massachusetts Institute of Technology |
| spellingShingle | Mechanical Engineering. Yin, Han, Ph.D. Massachusetts Institute of Technology Effect of synthesis conditions on large and persistent photoconductivity in chemical bath deposited cadmium sulfide thin films |
| title | Effect of synthesis conditions on large and persistent photoconductivity in chemical bath deposited cadmium sulfide thin films |
| title_full | Effect of synthesis conditions on large and persistent photoconductivity in chemical bath deposited cadmium sulfide thin films |
| title_fullStr | Effect of synthesis conditions on large and persistent photoconductivity in chemical bath deposited cadmium sulfide thin films |
| title_full_unstemmed | Effect of synthesis conditions on large and persistent photoconductivity in chemical bath deposited cadmium sulfide thin films |
| title_short | Effect of synthesis conditions on large and persistent photoconductivity in chemical bath deposited cadmium sulfide thin films |
| title_sort | effect of synthesis conditions on large and persistent photoconductivity in chemical bath deposited cadmium sulfide thin films |
| topic | Mechanical Engineering. |
| url | http://hdl.handle.net/1721.1/106772 |
| work_keys_str_mv | AT yinhanphdmassachusettsinstituteoftechnology effectofsynthesisconditionsonlargeandpersistentphotoconductivityinchemicalbathdepositedcadmiumsulfidethinfilms AT yinhanphdmassachusettsinstituteoftechnology ppcincdsthinfilms |