Abstract
We located the electrical junction (EJ) of Cu(In, Ga)Se2 (CIGS) and Cu2ZnSnSe4 (CZTS) solar cells with ∼20-nm accuracy using a scanning capacitance spectroscopy (SCS) technique. A procedure was developed to prepare the cross-sectional samples and grow critical high-quality insulating layers for the SCS measurement. We found that CIGS has a buried homojunction with the EJ located at ∼40 nm inside the CIGS/CdS interface. An n-type CIGS was probed in the region 10-30 nm away from the interface. By contrast, the CZTS/CdS cells have a heterointerface junction with a shallower EJ (∼20 nm) than CIGS. The EJ is ∼20 nm from the CZTS/CdS interface, which is consistent with asymmetrical carrier concentrations of the p-CZTS and n-CdS in a heterojunction cell. The unambiguous determination of the junction locations helped explain the large open circuit voltage difference between the state-of-the-art devices of CIGS and CZTS.
Original language | American English |
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Pages | 2298-2301 |
Number of pages | 4 |
DOIs | |
State | Published - 18 Nov 2016 |
Event | 43rd IEEE Photovoltaic Specialists Conference, PVSC 2016 - Portland, United States Duration: 5 Jun 2016 → 10 Jun 2016 |
Conference
Conference | 43rd IEEE Photovoltaic Specialists Conference, PVSC 2016 |
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Country/Territory | United States |
City | Portland |
Period | 5/06/16 → 10/06/16 |
Bibliographical note
Publisher Copyright:© 2016 IEEE.
NREL Publication Number
- NREL/CP-5K00-65748
Keywords
- CIGS
- CZTS
- electrical junction
- scanning capacitance spectroscopy