Two Low-Cost and Efficient Hole-Transporting Materials for n–i–p Type Organic–Inorganic Hybrid Perovskite Solar Cells

Abstract

The simpler the design, the better and more effective it is. Two novel conjugated triarylamine derivatives in donor−π–donor structure employing biphenyl core and pyrene core as π-bridges, which are termed as Bp-OMe and Py-OMe, have been synthesized and characterized and then applied to perovskite solar cells (PSCs) as hole-transport materials (HTMs) successfully. Using 2,2′,7,7′-tetrakis( N , N -di- p -methoxy-phenylamine)-9,9′-spirobiuorene (spiro-OMeTAD) as a relative reference, Py-OMe-based PSCs showed the best power conversion efficiency (PCE) of 19.28% under AM 1.5 G illumination at 100 mW cm –2 , which is comparable to that of PSCs based on spiro-OMeTAD with a best PCE of 18.57% with doping. Although Bp-OMe-based PSCs performed with relatively poor PCEs (best PCE of 15.06%) than those of Py-OMe-based PSCs, attributing to the poor planarity and hole mobility, taking the cost into consideration, Bp-OMe and Py-OMe are much more likely to be promising efficient HTMs for PSCs.

Efficiencyvs.stability: dopant-free hole transporting materials towards stabilized perovskite solar cells

“…18.2% PCE in planar PSCs has been achieved by employing disubstituted dly-2 , which is slightly higher in comparison with that in PSCs using tetrasubstituted derivatives. Very recently, another pyrene HTM Py-OMe comprising four triarylamine substituents was reported by Cui et al to achieve a PCE of 19.28% 116. Bridging the latter with extra thiophene units yielded OMe-TATPyr and further improved the photovoltaic performance over 20% 117.…”

Additive-free, Cost-Effective Hole-Transporting Materials for Perovskite Solar Cells Based on Vinyl Triarylamines

“…Moreover, conventional HTMs are too expensive for the mass production of low-cost PSCs . Cost-effective HTMs using low-cost reagents or efficient synthetic routes have been reported, − but in most cases, purification steps unsuited to industrial scale manufacture such as column chromatography were still required to obtain the isolated product. Thus, the development of truly cost-effective HTMs remains a crucial issue for commercial PSC production. , …”

Stable Perovskite Solar Cells Using Molecularly Engineered Functionalized Oligothiophenes as Low‐Cost Hole‐Transporting Materials

“…[23][24][25] Therefore, the development of cost-effective HTMs possessing excellent stability, appropriate highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels to transport holes and block electrons, respectively, is required for commercialization of perovskite solar cells. [26][27][28][29][30] Donor-π-donor configured HTMs such as benzene, [31] biphenyl, [32] thiophene, [33,34] fused thiophenes, [35][36][37] anthracene, [38] carbazole, [39] fluorene, [40] and bifluorenylidene [41] flanked by arylamine donors are extensively studied in PSCs to replace the expensive spiro-OMeTAD. The ease of synthesis and purification of HTMs have a direct impact on cutting the cost of the device.…”