Activated Electron-Transport Layers for Infrared Quantum Dot Optoelectronics.
Adv Mater
; : e1801720, 2018 May 28.
Article
em En
| MEDLINE
| ID: mdl-29808501
ABSTRACT
Photovoltaic (PV) materials such as perovskites and silicon are generally unabsorptive at wavelengths longer than 1100 nm, leaving a significant portion of the IR solar spectrum unharvested. Small-bandgap colloidal quantum dots (CQDs) are a promising platform to offer tandem complementary IR PV solutions. Today, the best performing CQD PVs use zinc oxide (ZnO) as an electron-transport layer. However, these electrodes require ultraviolet (UV)-light activation to overcome the low carrier density of ZnO, precluding the realization of CQD tandem photovoltaics. Here, a new sol-gel UV-free electrode based on Al/Cl hybrid doping of ZnO (CAZO) is developed. Al heterovalent doping provides a strong n-type character while Cl surface passivation leads to a more favorable band alignment for electron extraction. CAZO CQD IR solar cell devices exhibit, at wavelengths beyond the Si bandgap, an external quantum efficiency of 73%, leading to an additional 0.92% IR power conversion efficiency without UV activation. Conventional ZnO devices, on the other hand, add fewer than 0.01 power points at these operating conditions.
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Base de dados:
MEDLINE
Idioma:
En
Revista:
Adv Mater
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Canadá