Carbazole‐Based Hole‐Transport Materials for Efficient Solid‐State Dye‐Sensitized Solar Cells and Perovskite Solar Cells

Abstract

Two carbazole-based small molecule hole-transport materials (HTMs) are synthesized and investigated in solid-state dye-sensitized solar cells (ssDSCs) and perovskite solar cells (PSCs). The HTM X51-based devices exhibit high power conversion efficiencies (PCEs) of 6.0% and 9.8% in ssDSCs and PSCs, respectively. These results are superior or comparable to those of 5.5% and 10.2%, respectively, obtained for the analogous cells using the state-of-the-art HTM Spiro-OMeTAD.

Development of simple hole-transporting materials for perovskite solar cells

“…Simple, easy-tosynthesize HTMs have emerged with efficiencies rivalling spiro-OMeTAD in PSCs. [17][18][19] For example, a simple HTM known as "H101" was synthesized with a 3,4-ethylenedioxythiophene (EDOT) core and shown to achieve give respectable PCE of 10.6 % without the use of dopants. 17 In a subsequent paper, the same group reported a derivative of H101 with a tetra-substituted thiophene core (aka "H111") that achieved a PCE of 14.9 %.…”

Hole-transport materials with greatly-differing redox potentials give efficient TiO2–[CH3NH3][PbX3] perovskite solar cells

“…3,4 In response, there has been increased recent interest in developing new HTMs aimed at addressing these limitations. [3][4][5][6][7][8][9][10][11][12] This work has explored alternative HTM structures, in particular based on the triarylamine and carbazole motifs, 6-11 leading to impressive power-conversion efficiencies (PCE) reaching around 14%. (Fig.…”

“…Hole-transport materials with greatly-differing redox potentials give efficient TiO 2 -[CH 3 The recent development of lead halide perovskite based solar cells has led to a step change in the efficiencies of solution-processable solar cells culminating recently in certified power-conversion efficiencies reaching the range 16-18%. 1 The exceptional performance of these devices has been attributed to key properties of the perovskite layer including excellent electron and exciton mobility and direct band gap of appropriate energy for visible light harvesting.…”

“…2 To date, Spiro-OMeTAD has been most commonly used as the HTM in the highest efficiency cells, however this material requires an expensive multi-step synthesis and shows holetransport too low to carry all generated current. 3,4 In response, there has been increased recent interest in developing new HTMs aimed at addressing these limitations. [3][4][5][6][7][8][9][10][11][12] This work has explored alternative HTM structures, in particular based on the triarylamine and carbazole motifs, [6][7][8][9][10][11] leading to impressive power-conversion efficiencies (PCE) reaching around 14%.…”

“…3,4 In response, there has been increased recent interest in developing new HTMs aimed at addressing these limitations. [3][4][5][6][7][8][9][10][11][12] This work has explored alternative HTM structures, in particular based on the triarylamine and carbazole motifs, [6][7][8][9][10][11] leading to impressive power-conversion efficiencies (PCE) reaching around 14%. This involved Ullmann coupling to form the triarylamine fragment, followed by Sonogashira coupling to add a trimethylsilyl acetylide fragment and, after deprotection to remove the trimethylsilyl unit, a final oxidative homocoupling to form the central diacetylide unit (see ESI † for full details).…”