title: High-Efficiency Photovoltaic Devices using Trap-Controlled Quantum-Dot Ink prepared via Phase-Transfer Exchange.
abstract: Colloidal-quantum-dot (CQD) photovoltaic devices are promising candidates for low-cost power sources owing to their low-temperature solution processability and bandgap tunability. A power conversion efficiency (PCE) of >10% is achieved for these devices; however, there are several remaining obstacles to their commercialization, including their high energy loss due to surface trap states and the complexity of the multiple-step CQD-layer-deposition process. Herein, high-efficiency photovoltaic devices prepared with CQD-ink using a phase-transfer-exchange (PTE) method are reported. Using CQD-ink, the fabrication of active layers by single-step coating and the suppression of surface trap states are achieved simultaneously. The CQD-ink photovoltaic devices achieve much higher PCEs (10.15% with a certified PCE of 9.61%) than the control devices (7.85%) owing to improved charge drift and diffusion. Notably, the CQD-ink devices show much lower energy loss than other reported high-efficiency CQD devices. This result reveals that the PTE method is an effective strategy for controlling trap states in CQDs.
authors.affiliation: Department of Chemistry, Kookmin University, 77 Jeongneung-ro, Seongbuk-gu, Seoul, 136-702, Republic of Korea.
authors.forename: Havid
authors.initials: H
authors.lastname: Aqoma
authors.affiliation: Department of Chemistry, Kookmin University, 77 Jeongneung-ro, Seongbuk-gu, Seoul, 136-702, Republic of Korea.
authors.forename: Muhibullah
authors.initials: M
authors.lastname: Al Mubarok
authors.affiliation: Department of Chemistry, Kookmin University, 77 Jeongneung-ro, Seongbuk-gu, Seoul, 136-702, Republic of Korea.
authors.forename: Wisnu Tantyo
authors.initials: WT
authors.lastname: Hadmojo
authors.affiliation: Soft Innovative Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Joellabuk-do, 565-905, Republic of Korea.
authors.forename: Eun-Hye
authors.initials: EH
authors.lastname: Lee
authors.affiliation: Soft Innovative Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Joellabuk-do, 565-905, Republic of Korea.
authors.forename: Tae-Wook
authors.initials: TW
authors.lastname: Kim
authors.affiliation: Department of Energy Science, Sungkyunkwan University, 2066 Seobu-Ro, Jangsan-Gu, Suwon, 440-746, Republic of Korea.
authors.forename: Tae Kyu
authors.initials: TK
authors.lastname: Ahn
authors.affiliation: Radiation Research Division for Industry and Environment, Korea Atomic Energy Research Institute (KAERI), 29 Geumgu-gil, Jeongeup-si, Jeollabuk-do, 580-185, Korea.
authors.forename: Seung-Hwan
authors.initials: SH
authors.lastname: Oh
authors.affiliation: Department of Chemistry, Kookmin University, 77 Jeongneung-ro, Seongbuk-gu, Seoul, 136-702, Republic of Korea.
authors.forename: Sung-Yeon
authors.initials: SY
authors.lastname: Jang
keywords: phase-transfer exchange; quantum dots; solar cells; surface traps; voltage loss