title: Emerging of Inorganic Hole Transporting Materials For Perovskite Solar Cells.
abstract: Hole transporting material (HTM) is a significant component to achieve the high performance perovskite solar cells (PSCs). Over the years, inorganic, organic and hybrid (organic-inorganic) material based HTMs have been developed and investigated successfully. Today, perovskite solar cells achieved the efficiency of 22.1 % with with 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenyl-amine) 9,9-spirobifluorene (spiro-OMeTAD) as HTM. Nevertheless, synthesis and cost of organic HTMs is a major challenging issue and therefore alternative materials are required. From the past few years, inorganic HTMs showed large improvement in power conversion efficiency (PCE) and stability. Recently CuOxreached the PCE of 19.0% with better stability. These developments affirms that inorganic HTMs are better alternativesto the organic HTMs for next generation PSCs. In this report, we mainly focussed on the recent advances of inorganic and hybrid HTMs for PSCs and highlighted the efficiency and stability of PSCs improved by changing metal oxides as HTMs. Consequently, we expect that energy levels of these inorganic HTMs matches very well with the valence band of perovskites and improved efficiency helps in future practical deployment of low cost PSCs.
authors.affiliation: Inorganic & Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology (IICT), Tarnaka, 500007, Telangana, India.
authors.forename: Ramireddy
authors.initials: R
authors.lastname: Rajeswari
authors.affiliation: Inorganic & Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology (IICT), Tarnaka, 500007, Telangana, India.
authors.forename: Madoori
authors.initials: M
authors.lastname: Mrinalini
authors.affiliation: Inorganic & Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology (IICT), Tarnaka, 500007, Telangana, India.
authors.forename: Seelam
authors.initials: S
authors.lastname: Prasanthkumar
authors.affiliation: Inorganic & Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology (IICT), Tarnaka, 500007, Telangana, India.|Academy of Scientific and Innovative Research (AcSIR), New Delhi, India.
authors.forename: Lingamallu
authors.initials: L
authors.lastname: Giribabu
keywords: Efficiency; Inorganic HTM; Morphology; Perovskite solar cells; Stability