An Ultraviolet‐Deposited MoO₃ Film as Anode Interlayer for High‐Performance Polymer Solar Cells

Abstract

An ultraviolet‐deposited MoO3 film is developed as anode interlayer based on molybdenum(V) chloride as precursor. The ultraviolet‐deposited MoO3 film is prepared from the precursor film (spin coated from its solution) with ultraviolet irradiation treatment, and the preparation process of the MoO3 film is facile, low cost, and compatible with mass production and flexible substrate. The composition of the MoO3 film is analyzed by X‐ray photoelectron spectroscopy. The work function as well as the surface morphology and wettability of indium tin oxide (ITO) modified by the MoO3 film are investigated by ultraviolet photoelectron spectroscopy, atomic force microscopy, and contact angle tester, respectively, where the analyses show the ITO modified by the MoO3 anode interlayer can offer excellent energy level alignment and interface contact with active layer. The photovoltaic performance of nonfullerene polymer solar cells (PSCs) based on the MoO3 anode interlayer is researched with typical and relatively low‐cost PBDB‐T:ITIC as active layer, and the ITO/MoO3‐based device shows the highest power conversion efficiency of 9.27% compared with the bare ITO‐based device (3.69%) and the ITO/PEDOT:PSS‐based device (9.15%). The results demonstrate the great potential of the ultraviolet‐deposited MoO3 film as anode interlayer for high‐performance PSCs.

Cross-Linkable and Alcohol-Soluble Pyridine-Incorporated Polyfluorene Derivative as a Cathode Interface Layer for High-Efficiency and Stable Organic Solar Cells

“…The current density−voltage (J− V) curves and external quantum efficiency (EQE) of OSCs were measured in air using commercial measurement systems according to previous reports. 7,26 The photostability of OSCs was evaluated by measuring the PCE evolution of the encapsulated devices placed under a continuous illumination of 100 mW cm −2 in air. The thermal cycling stability of OSCs was evaluated by measuring the PCE evolution of the encapsulated devices subjected to thermal cycle stress, where a complete thermal cycle mainly consisted of two stages:…”

“…Organic solar cells (OSCs) have emerged as a promising photovoltaic technology due to their unique advantages including being light weight and flexible and having great potential in printing processing. − With multiple synergistic improvements in photovoltaic materials (particularly nonfullerene acceptors), active layer morphology, device design, and interface modification, OSCs have achieved an excellent power conversion efficiency (PCE) of more than 17%. − However, commercial applications of OSCs are still severely hindered by issue of device stability, especially the environmental stability of OSCs under standard operating environments in real-world outdoor applications. − The photovoltaic performance of OSCs is usually decreased by photovoltaic materials degradation and active layer morphology evolution induced by light, heat, moisture, etc. − In addition, the device stability of OSCs is also strongly influenced by the characteristics of the interface layers between the electrode and the active layer. − Compared with conventional OSCs with a typical PEDOT:PSS anode interface layer (AIL), OSCs utilizing an inverted device structure with MoO 3 AIL usually possess superior device stability. , Moreover, a suitable cathode interface layer (CIL) between the ITO cathode and the active layer also plays a key role in the efficiency and stability of inverted OSCs (i-OSCs). − …”

Recent Advances in Hole-Transporting Layers for Organic Solar Cells

“…This radiation decomposed O 3 into O 2 and active O, which oxidized and removed any organic contaminant by transformation into volatile gases. Cai et al achieved a PCE of 9.27% in the PBDB-T:ITIC BHJ cell using an ultraviolet-deposited MoO 3 film [ 106 ]. Tan et al developed a solution-processed, annealing-free aqueous MoO x for non-fullerene OSCs [ 107 ].…”

Hole/Electron Transporting Materials for Nonfullerene Organic Solar Cells

“…Chen et al. employed Molybdenum(V) chloride (MoCl 5 ) as the precursor to prepare the MoO x film by ultraviolet irradiation and a mild temperature annealing (100 °C), which showed superior photovoltaic performance in comparison with the devices based on ITO/PEDOT:PSS [83c] . Ma et al.…”