title: Influence of External Pressure on the Performance of Quantum Dot Solar Cells.
abstract: We report the influence of post-treatment via the external pressure on the device performance of quantum dot (QD) solar cells. The structural analysis together with optical and electrical characterization on QD solids reveal that the external pressure compacts QD active layers by removing the mesoscopic voids and enhances the charge carrier transport along QD solids, leading to significant increase in JSC of QD solar cells. Increasing the external pressure, by contrast, accompanies reduction in FF and VOC, yielding the trade-off relationship among JSC and FF and VOC in PCE of devices. Optimization at the external pressure in the present study at 1.4-1.6 MPa enables us to achieve over 10% increase in PCE of QD solar cells. The approach and results show that the control over the organization of QDs is the key for the charge transport properties in ensemble and also offer simple yet effective mean to enhance the electrical performance of transistors and solar cells using QDs.
authors.affiliation: Department of Electrical and Computer Engineering, Global Frontier for Multiscale Energy Systems, Seoul National University , Seoul 08826, Republic of Korea.
authors.forename: Jaehoon
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Chemical and Biomolecular Engineering (BK21+ Program), KAIST Institute for the Nanocentury, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Republic of Korea.
authors.forename: Byeong Guk
authors.initials: BG
authors.lastname: Jeong
authors.affiliation: Department of Electrical and Computer Engineering, Global Frontier for Multiscale Energy Systems, Seoul National University , Seoul 08826, Republic of Korea.
authors.forename: Heebum
authors.initials: H
authors.lastname: Roh
authors.affiliation: Department of Electrical and Computer Engineering, Global Frontier for Multiscale Energy Systems, Seoul National University , Seoul 08826, Republic of Korea.
authors.forename: Jiyun
authors.initials: J
authors.lastname: Song
authors.affiliation: Department of Electrical and Computer Engineering, Global Frontier for Multiscale Energy Systems, Seoul National University , Seoul 08826, Republic of Korea.
authors.forename: Myeongjin
authors.initials: M
authors.lastname: Park
authors.affiliation: Department of Chemical and Biomolecular Engineering (BK21+ Program), KAIST Institute for the Nanocentury, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Republic of Korea.
authors.forename: Doh C
authors.initials: DC
authors.lastname: Lee
authors.affiliation: Photo-Electronic Hybrids Research Center, Korea Institute of Science and Technology (KIST) , Seoul 02792, Republic of Korea.
authors.forename: Wan Ki
authors.initials: WK
authors.lastname: Bae
authors.affiliation: Department of Electrical and Computer Engineering, Global Frontier for Multiscale Energy Systems, Seoul National University , Seoul 08826, Republic of Korea.
authors.forename: Changhee
authors.initials: C
authors.lastname: Lee
keywords: compression; densification; pressure; quantum dots; solar cells