An efficient hole transport material composite based on poly(3-hexylthiophene) and bamboo-structured carbon nanotubes for high performance perovskite solar cells

Abstract

In this work, we have developed a new efficient hole transport material (HTM) composite based on poly(3-hexylthiophene) (P3HT) and bamboo-structure carbon nanotubes (BCN) for CH 3 NH 3 PbI 3 (MAPbI 3 ) based perovskite solar cells. Compared to pristine P3HT, it is found that the crystallinity of P3HT was significantly improved by addition of BCN, which led to over one order of magnitude higher conductivity for the composite containing 1-2wt% BCN in P3HT. In the meantime, the interfacial charge transfer between the MAPbI 3 light absorbing layer and the HTM composite layer based on the P3HT/BCNs was two-fold faster than pristine P3HT. More importantly, the HTM film with superior morphological structure consisting of closely compact large grains was achieved with the composite containing 1wt% BCNs in P3HT. The study by electrochemical impedance spectroscopy has confirmed that the electron recombination in the solar cells was reduced nearly ten-fold with the addition of 1wt% carbon nanotubes in the HTM composite. Owing to the superior HTM film morphology and the significantly reduced charge recombination, the energy conversion efficiency of the perovskite solar cells increased from 3.6% for pristine P3HT to 8.3% for P3HT/(1wt% BCNs) with a significantly enhanced open circuit voltage (V oc ) and fill factor (FF). The findings of this work are important for development of new HTM for high performance of perovskite solar cells.

Under the spotlight: The organic–inorganic hybrid halide perovskite for optoelectronic applications

“…3.12. Typically, PSS:PEDOT is used for inverted configurations and polythiophenes and their derivative poly(3-hexylthiophene-2,5-diyl) (P3HT) [84,136,[213][214][215][216][217][218][219][220][221][222][223][224][225][226][227][228] are employed for normal structures. PSS:PEDOT is a widely used electron blocking layer due to its excellent transparency, work function, conductivity and chemical stability.…”

“…As a result, the active layer of perovskite showed pristine crystallinity after 96 h of exposure to air. In a similar work, CNTs were blended with P3HT in order to enhance conductivity [214]. The P3HT-CNT composites were dissolved in dichlorobenzene and then spin-coated onto perovskite/TiO 2 film serving as the HTL.…”

Dopant‐Free Donor (D)–π–D–π–D Conjugated Hole‐Transport Materials for Efficient and Stable Perovskite Solar Cells

“…Due to its relatively low hole mobility and its tedious synthesis strongly correlated to its production cost, numerous alternative HTMs have been explored with an aim to replace such a material [9][10][11][12][13][14][15][16][17][18][19][20] . Although inorganic HTMs (CuI and CuSCN) have drawn much attention due to their high hole mobilities and low production cost [21] ,polymeric HTMs, such as conjugated polytriarylamine (PTAA) [22] , poly(3-hexylthiophene-2,5-diyl) (P3HT) [23] etc., have also shown competitive performances in PSCs, small molecular HTMs have advantages of their convenient purification, controllable molecular structures and relatively high efficiency [24] .Regarding small molecule HTMs incorporated with dopants, the PCE of the dopant-free HTM based devices are consistently lying between 10% to 13% [25][26][27][28][29][30][31][32][33][34][35][36] , few are over 15%. [37][38][39][40] Herein, we report the synthesis and characterization of three novel dopant-free 4-Methoxytriphenylamine (MeOTPA) -based HTMs as shown in Figure 1a, Figure 1b and experimental details are given in the Experimental Section.…”

Extending the environmental lifetime of unpackaged perovskite solar cells through interfacial design

“…7,8 In addition, oxygen has been found to have only little effect on the degradation of perovskite devices. 2 ) have been developed. [9][10][11] Recently, it has also been suggested that cross-linking perovskite grains with phosphonic acid ammonium derivatives may further decrease the moisture sensitivity of perovskite devices.…”

“…[1][2][3] Device operational lifetime is the third corner of the magic triangle evaluating the performance potential of photovoltaic technologies, and this is of particular concern for the perovskite-based technology owing to its water soluble Pb-salt component. 4,5 Limited shelf as well as operational lifetime have been reported in the early stages of perovskite research and appeared to be one of the major roadblocks towards further driving this technology.…”