The saturation of VOC at larger band gaps in Cu(In, Ga)Se2 devices presents a major challenge in developing high efficiency solar devices for tandem solar applications. Although recent studies have shown that recombination at the buffer/absorber interface dominates in high Ga samples with wide band gaps, the interface parameters are not well understood to accurately model the device behavior. In this work we have applied temperature dependent CV and DLCP methods to estimate the interface state density along the bandgap in CIGS and CIAGS based solar devices. We have also used DLTS to study the nature of deep levels in CIGS and CIAGS devices. Based on our analysis and device simulation results, we attribute the VOC saturation in wide gap CIAGS devices to increased recombination rate at the interface.
|Original language||English (US)|
|Title of host publication||2017 IEEE 44th Photovoltaic Specialist Conference, PVSC 2017|
|Publisher||Institute of Electrical and Electronics Engineers Inc.|
|Number of pages||6|
|State||Published - 2017|
|Event||44th IEEE Photovoltaic Specialist Conference, PVSC 2017 - Washington, United States|
Duration: Jun 25 2017 → Jun 30 2017
|Name||2017 IEEE 44th Photovoltaic Specialist Conference, PVSC 2017|
|Other||44th IEEE Photovoltaic Specialist Conference, PVSC 2017|
|Period||6/25/17 → 6/30/17|
Bibliographical noteFunding Information:
This project is supported by the Sunshot program of Department of Energy Sunshot program (Award DE-EE0005319). The device fabrication was performed in Minnesota Nano Center (MNC) under partial support of the National Nano Coordinated Infrastructure program at NSF.
© 2017 IEEE.
- Electrical Characterization
- SCAPS modeling
- Wide band-gap solar cells