are mainly due to the higher LUMO of -3.74 eV (ICBA) and -3.72 eV (IC 70 BM) compared with that of PC 61 BM (-3.91 eV). However, further improvement of V oc of P3HT-based organic solar cell by modulation of fullerene is quite difficult and usually leads to the decrease the performance.On the other hand, non-fullerene acceptors have been intensively investigated and some exciting results have been obtained in recent three years, due to their adjustable absorption spectra and energy levels. [5] High PCEs of over 10% have been realized by optimizing both donor materials and nonfullerene acceptors. [6] Furthermore, to combine with classic P3HT donor polymer, electron-deficient building blocks, such as benzothiadiazole (BT), [7] diketopyrrolopyrrole (DPP), [8] perylene diimide, [9] naphthalene diimide, [10] other rylene imide, [11] and other electron-deficient building blocks [12] have been widely adopted to construct non-fullerene acceptors. The V oc and PCE of solar cells based on reported P3HT:non-fullerene small molecule acceptors are summarized in Figure 1. From Figure 1, although many kinds of non-fullerene acceptors were developed, but only five samples could realize a PCE of beyond 4% (typical value for P3HT:PCBM system). In addition, it clearly shows that the V oc could be easily improved to even beyond 1.0 V, but only one sample based on DPP segment could simultaneously achieve a V oc of higher than 1.0 V and a PCE of higher than 4%. [8e] Very recently, the highest PCE of P3HTbased solar cells reached 6.4% with a V oc of 0.8 V by using one BT-containing non-fullerene acceptor. [7f ] Thus, the development of novel non-fullerene acceptor to match well with P3HT is still urgent and necessary for the further application of P3HT-based OSCs.It is well known that benzo[d][1,2,3]triazole (BTA) has the similar chemical structure with BT and BTA-based p-type photovoltaic polymers showed ultra-high PCEs of 7.1%-8.4% and 8.2 BTA-9.5% respectively, when they are combined with fullerene derivatives [13] or non-fullerene acceptors. [14] Comparative to p-type polymers, however, BTA-containing n-type polymers show inferior PCEs of 0.18%-0.4%, [15] and there is also no report of BTA-based non-fullerene small molecule acceptors. In principle, BTA is a weaker electron-withdraw building block than BT, which could up-shift the LUMO energy levels of final materials. Furthermore, the alkyl chain in BTA could also finetune the solubility and crystallinity of final small molecules.Thus, in this communication, we adopted common A 2 A 1 DA 1 A 2 linear molecular structure to design and synthesize the first BTA-containing non-fullerene small molecule acceptor, where rhodanine (R), BTA and indacenodithiophene (IDT) were used as terminal acceptor (A 2 ), bridge acceptor (A 1 ), and central donor (D), respectively. This small molecule, named Organic solar cells (OSCs) have attracted much attention in the last two decades due to their ease of processing, mechanical flexibility, and potential for large-scale low cost fabrication. Afte...

Machine learning (ML) is a field of computer science that uses algorithms and techniques for automating solutions to complex problems that are hard to program using conventional programming methods. Owing...

This article is written to provide an up-to-date review of porphyrin-based materials used in organic solar cells (OSCs).

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