9.05% HTM free perovskite solar cell with negligible hysteresis by introducing silver nanoparticles encapsulated with P4VP polymer

Abstract

This study is a follow up to our previously published manuscript on "improved power conversion efficiency in Perovskite solar cell using silver nanoparticles modified photoanode". Three more photoanodes were fabricated which are: Ag@ P 4 VP NPs mixed with perovskite layer (S2), Ag@P 4 VP NPs simultaneously mixed both in TiO 2 and perovskite films (S3) and P25 NP simultaneously mixed both in TiO 2 and perovskite absorber (S4) and their performances were investigated systematically. The performance, especially the photocurrent, and open circuit voltage of PSCs made of Ag@P 4 VP NPs were significantly affected. The champion device is S3, which shows enhancement in power conversion efficiency (PCE) from 3.80 to 9.05%, short circuit current density (Jsc) from 11.04 to 15.87 mA cm −2 , open circuit voltage (Voc) from 0.85 to 0.88 and fill factor (FF) from 0.41 to 0.65, which demonstrates ~ 2.38 times improvement in PCE over the control device (C). When Ag@P 4 VP NPs was mixed with TiO 2 , PCE of 5.69%, Jsc of 12.61 mA cm −2 , Voc of 0.88 V and FF of 0.51 were achieved, which shows ~ 1.50 times improvement over the performance of the reference cell. Also, when Ag@P 4 VP NPs was mixed with the perovskite layer, PCE of 8.08%, Jsc of 14.18 mA cm −2 , Voc of 0.89 V and FF of 0.64 were achieved, which shows ~ 2.13 times improvement over the performance of the pristine device. The addition of Ag@P 4 VP NPs enhanced exciton generation and dissociation, encouraging charge separation/transfer, as well as reducing quenching losses. For the hysteresis test, it was found that the devices with Ag@P 4 VP NPs have almost identical J-V curves with negligible hysteresis, which is attributed to the significant reduction of the trap density of the perovskite film when Ag@P 4 VP NPs is incorporated to fill the pores with high trapping rate. We however observed hysteretic behavior in devices C and S4, which makes it difficult to estimate the real PCE.

Numerical Modeling and Analysis of HTM-Free Heterojunction Solar Cell Using SCAPS-1D

“…Under illumination, a J sc of 21.96 mAcm −2 , Voc of 0.86 V, FF of 69.94 %, and PCE of 13.22 % are obtained. The V oc simulated in this studies agrees with V oc (0.85 V) in experimental work demonstrated by a group of researchers [9]. However, the values of PCE, FF and J sc are higher than ones obtained from experimental research work, this may be due to the lesser series resistance arising from pt metal contact or FTO and the optical reflectance is considered to be zero at the surface and at each interface during our simulation [25].…”

“…Optical absorption edge is red shifted to 800 nm which corresponds to a band gap of 1.55 eV in CH 3 NH 3 PbI 3 . The QE sweeps across the whole visible spectrum which to an extent agrees with experimental work [9].…”

“…Several advantages of perovskite absorber have made it a choice of candidate for application photovoltaic structures, among which include, tuned band gap, small exciton energy, excellent bipolar carrier transport, long electron-hole diffusion, and amazingly high tolerance to defects [1][2][3][4][5][6][7]. The properties exhibited by this material in solar cells results to enhanced power conversion efficiency from 3.9 % [8] to over 25 % [9]. However, some draw backs such as instability, electron transport resistance between TiO2 and perovskite absorber and the use of costly hole transport material (HTM) (such as spiro-Omeotad) has prevented its outdoor usage.…”

“…Also, in 2014, Li et al [14] followed the same route by replacing metal back contact with laminated carbon nanotubes (CNTs) to collect holes from absorber and block electrons from ETM and results to a PCE of 6.87%. Eli et al [9] developed a PSC without HTM with elcocarb as metal back contact to collect hole and realized a PCE of 3.80 %.…”

Synergistic Study of Reduced Graphene Oxide as Interfacial Buffer Layer in HTL-free Perovskite Solar Cells with Carbon Electrode

“…In 2013, Han's group reported for the first time in literature, a Hole Transport Material (HTM)-free mesoscopic PSCs with carbon electrode as replacement to Spiro-OMeTAD with PCE of 6.64 % [8,9]. This architecture has been widely studied with several modifications owing to their relatively low production cost and low hysteresis [2,10]. In addition, mesoscopic HTL-free PSCs are characterized by their long-term stability and therefore makes them a more suitable and promising architecture for commercialization [2,6,[11][12][13].…”