Sulfur Position in Pyrene-Based PTTIs Plays a Key Role To Determine the Performance of Perovskite Solar Cells When PTTIs Were Employed as Electron Transport Layers

Abstract

In this study, two novel small organic molecules (PTTI-1 and PTTI-2, the difference between them is the position of sulfur atom in thieno [3,4-b]thiophene(TT)) are designed and synthesized through introduction of the pyrene unit as the central building block and TT as the conjugated linking units. The as-prepared compounds have been demonstrated as electron transport layers (ETLs) for perovskite solar cells (PSCs), and PTTI-1 shows a better power conversation efficiency (PCE) value of 15.37%, higher than that of PTTI-2 (11.07%), which may be due to the suitable energy level, strong passivation behavior, and higher electron mobility of PTTI-1. Our study clearly indicates that the sulfur position in this type of electron-transport materials plays an important role in influencing the performance of PSCs. More importantly, our devices show decent stability, where PTTI-1-based devices retain about 83% of its initial stability after 10 days of testing.

Influences of Structural Modification of Naphthalenediimides with Benzothiazole on Organic Field-Effect Transistor and Non-Fullerene Perovskite Solar Cell Characteristics

“…By investigating τ 1 of each molecule on the perovskite layer, it is noted that the extraction of electrons from the perovskite layer by NDI-BTH2 is little faster than NDI-BTH1. The longer lifetime τ 2 of the NDI-BTH2/perovskite bilayer than that of NDI-the BTH1/perovskite bilayer indicated that NDI-BTH2 has a stronger passivation property toward electron trap centers than NDI-BTH1. , In perovskite/NDI-BTH1 and perovskite/NDI-BTH2 bilayers, the lifetimes τ 1 are 8.86 and 8.62 ns, respectively. The PL lifetimes for these ETLs on the FA y MA 1– y PbI 3– x Cl x layer were found to significantly decrease compared to that of the bare perovskite layer (Table ).…”

Indene-C60 Bisadduct Electron-Transporting Material with the High LUMO Level Enhances Open-Circuit Voltage and Efficiency of Tin-Based Perovskite Solar Cells

“…Dark J – V curves of the solar cells show that the reverse current density is the smallest with the introduction of ICBA ETL, indicating that charge carriers better pass through this device rather than direct shunting (Figure S11b). The reduced leakage current and depressed charge-carrier recombination jointly contribute to the improvement in FF for the solar cell device equipped with an ICBA ETL.…”

“…Dark J−V curves of the solar cells show that the reverse current density is the smallest with the introduction of ICBA ETL, indicating that charge carriers better pass through this device rather than direct shunting (Figure S11b). 63 The reduced leakage current and depressed charge-carrier recombination jointly contribute to the improvement in FF for the solar cell device equipped with an ICBA ETL. ICBA-based solar cells exhibit a slightly lower EQE than the C 60 -and PCBM-based ones in the spectral range of 300−950 nm (Figure 3c), indicating its relatively lower charge extraction efficiency than the others.…”

A perylene diimide dimer-based electron transporting material with an A–D–A structure for efficient inverted perovskite solar cells

“…Alternatively, some non-fullerene electron transport materials with high electron mobilities, tunable energy levels and uniform morphology were investigated. 35–42 Among them, perylene diimide ( PDI ) derivatives as electron-withdrawing and planar π-conjugated systems are classical organic semiconductors with high electron mobilities, excellent thermal stability and simplified synthesis routes. 43–47 Moreover, they can provide diimide groups to coordinate with the uncoordinated Pb 2+ , passivating traps on the surface of perovskite crystal grains, thus leading to the enhancement of conversion efficiency and device stability.…”