title: Perovskite Solar Cells: Influence of Hole Transporting Materials on Power Conversion Efficiency.
abstract: The recent advances in perovskite solar cells (PSCs) created a tsunami effect in the photovoltaic community. PSCs are newfangled high-performance photovoltaic devices with low cost that are solution processable for large-scale energy production. The power conversion efficiency (PCE) of such devices experienced an unprecedented increase from 3.8 % to a certified value exceeding 20 %, demonstrating exceptional properties of perovskites as solar cell materials. A key advancement in perovskite solar cells, compared with dye-sensitized solar cells, occurred with the replacement of liquid electrolytes with solid-state hole-transporting materials (HTMs) such as 2,2',7,7'-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene (Spiro-OMeTAD), which contributed to enhanced PCE values and improved the cell stability. Following improvements in the perovskite crystallinity to produce a smooth, uniform morphology, the selective and efficient extraction of positive and negative charges in the device dictated the PCE of PSCs. In this Review, we focus mainly on the HTMs responsible for hole transport and extraction in PSCs, which is one of the essential components for efficient devices. Here, we describe the current state-of-the-art in molecular engineering of hole-transporting materials that are used in PSCs and highlight the requisites for market-viability of this technology. Finally, we include an outlook on molecular engineering of new functional HTMs for high efficiency PSCs.
authors.affiliation: Energy Materials & Surface Science Laboratory, Solar Energy Research Center, School of Chemical Engineering, Chonbuk National University, Jeonju, 561-756, Republic of Korea.
authors.forename: Sadia
authors.initials: S
authors.lastname: Ameen
authors.affiliation: Center of Excellence for Advanced Materials Research (CEAMR), King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Malik Abdul
authors.initials: MA
authors.lastname: Rub
authors.affiliation: Center of Excellence for Advanced Materials Research (CEAMR), King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Samia A
authors.initials: SA
authors.lastname: Kosa
authors.affiliation: Center of Excellence for Advanced Materials Research (CEAMR), King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Khalid A
authors.initials: KA
authors.lastname: Alamry
authors.affiliation: New & Renewable Energy Material Development Center (NewREC), Chonbuk National University, Jeonbuk, Republic of Korea.
authors.forename: M Shaheer
authors.initials: MS
authors.lastname: Akhtar
authors.affiliation: Energy Materials & Surface Science Laboratory, Solar Energy Research Center, School of Chemical Engineering, Chonbuk National University, Jeonju, 561-756, Republic of Korea.
authors.forename: Hyung-Shik
authors.initials: HS
authors.lastname: Shin
authors.affiliation: Energy Materials & Surface Science Laboratory, Solar Energy Research Center, School of Chemical Engineering, Chonbuk National University, Jeonju, 561-756, Republic of Korea.
authors.forename: Hyung-Kee
authors.initials: HK
authors.lastname: Seo
authors.affiliation: Center of Excellence for Advanced Materials Research (CEAMR), King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Abdullah M
authors.initials: AM
authors.lastname: Asiri
authors.affiliation: Group for Molecular Engineering of Functional Materials, Institute of Chemical Science and Engineering, École Polytechnique fédérale de Lausanne, Station 6, CH-1015, Lausanne, Switzerland. MdKhaja.Nazeeruddin@epfl.ch.
authors.forename: Mohammad Khaja
authors.initials: MK
authors.lastname: Nazeeruddin
mesh_terms: D017610:Calcium Compounds / Q000737:chemistry*; D011211:Electric Power Supplies; D008962:Models, Theoretical; D010087:Oxides / Q000737:chemistry*; D010777:Photochemistry; D012993:Solar Energy; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D017610:Calcium Compounds; D010087:Oxides; C059910:perovskite; D014025:Titanium
keywords: device structure; hole transport; molecular engineering; perovskite; solar cells