A Colloidal-Quantum-Dot-Based Self-Charging System via the Near-Infrared Band

Se-Woong Baek; Jungmin Cho; Joo-Seong Kim; Changjo Kim; Kwangmin Na; Sang-Hoon Lee; Sunhong Jun; Jung Hoon Song; Sohee Jeong; Jang Wook Choi; Jung-Yong Lee

doi:10.1002/adma.201707224

A Colloidal-Quantum-Dot-Based Self-Charging System via the Near-Infrared Band

Adv Mater. 2018 Jun;30(25):e1707224. doi: 10.1002/adma.201707224. Epub 2018 May 11.

Authors

Affiliations

¹ Graduate School of Energy, Environment, Water, and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
² Department of Chemistry, Northwestern University, Evanston, IL, 60208, USA.
³ Nanomechanical Systems Research Division, Korea Institute of Machinery and Materials (KIMM), Daejeon, 34103, Republic of Korea.
⁴ Department of Nanomechatronics, Korea University of Science and Technology (UST), Daejeon, 34113, Republic of Korea.
⁵ School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea.

PMID: 29748976
DOI: 10.1002/adma.201707224

Abstract

A novel self-charging platform is proposed using colloidal-quantum-dot (CQD) photovoltaics (PVs) via the near-infrared (NIR) band for low-power electronics. Low-bandgap CQDs can convert invisible NIR light sources to electrical energy more efficiently than wider spectra because of reduced thermalization loss. This energy-conversion strategy via NIR photons ensures an enhanced photostability of the CQD devices. Furthermore, the NIR wireless charging system can be concealed using various colored and NIR-transparent fabric or films, providing aesthetic freedom. Finally, an NIR-driven wireless charging system is demonstrated for a wearable healthcare bracelet by integrating a CQD PVs receiver with a flexible lithium-ion battery and entirely embedding them into a flexible strap, enabling permanent self-charging without detachment.

Keywords: colloidal quantum dots; flexible Li-ion batteries; near-infrared (NIR); photostability; wearable electronics.