High-performance printable hybrid perovskite solar cells with an easily accessible n-doped fullerene as a cathode interfacial layer

Abstract

Engineering the interface between the active layer and the electrodes has proven to be a promising strategy to enhance the power conversion efficiency (PCE) of hybrid perovskite solar cells (PeSCs). Here, we present an effective approach to achieve highly efficient PeSCs by inserting an easy-accessible hexamethonium bromide (HMB)-doped [6,6]-phenyl-C-butyric acid methyl ester (PCBM) film between the active perovskite layer and the Ag cathode. This doped interfacial layer delivers several remarkable features for use in PeSCs, including solution processability, good electrical conductivity, fine work-function tunability of the Ag electrode, and general applicability to different fullerene materials. As a consequence, planar-heterojunction PeSCs deliver a PCE up to ∼18%, showing an approximately 5.6-fold enhancement compared with the control device using an undoped PCBM layer. In particular, benefitting from the high conductivity of this doped film, a prominent PCE as high as 15.58% can be achieved even when a large thickness of the PCBM layer (120 nm) is used. To the best of our knowledge, this is the highest performance ever reported for PeSCs with a PCBM thickness more than 100 nm. More encouragingly, large-area PeSCs (active area = 1.2 cm) via the doctor-blade coating technique also exhibit a remarkable PCE (15.23%) and good long-term stability under an inert atmosphere. Our results indicate that the HMB-doped PCBM film is a promising interfacial layer for PeSCs and can be compatible with high throughput roll-to-roll manufacturing processes.

Additive and Interface Engineering via Crosslinked 3D Polymer Network for Efficient and Stable Perovskite Solar Cells

“…For instance, we have demonstrated a series of n-doped cathode interfacial layer materials for PeSC, and significant advancement in device efficiency and stability has been made. [19][20][21][22][23][24] In this study, for the first time, we propose a facile strategy to increase the performance and stability of PeSC by incorporating tri(ethylene glycol) divinyl ether (TEGDVE; see Figure 1a for its chemical structure) as the additive and dopant for methylammonium lead iodide (MAPbI 3 ) perovskite active layer and alcoholsoluble nonfullerene amine-functionalized perylene diimide (PDIN; see Figure 1a for its chemical structure) cathode interfacial layer, respectively. The perovskite layer is fabricated by the two-step sequential deposition method (Figure 1a) based on our previous study, [19][20][21][22][23][24] except that TEGDVE additive is incorporated into moniumiodide (MAI) solution in this work.…”

“…For instance, we have demonstrated a series of n‐doped cathode interfacial layer materials for PeSC, and significant advancement in device efficiency and stability has been made. [ 19–24 ]…”

Efficient and Stable Vacuum‐Free‐Processed Perovskite Solar Cells Enabled by a Robust Solution‐Processed Hole Transport Layer

“…For the blade-coated devices, the devices were fabricated according to our previous study. [43] Briefly,P bI 2 (15 mL) complex solution (1.1 m in anhydrous dimethylformamide) was dispensed from as yringe under the edge of the blade fixed at 100 mma bove the substrate surface, and the blade was dragged at ac onstant speed of 70 mm s À1 .I t should be noted that the substrates were heated at an elevated temperature of 80 8Cd uring the blade deposition to obtain compact film with good uniformity.F APbI 3 crystallization was achieved by dipping the PbI 2 -coated samples into the FAIs olution (20 mg mL À1 in anhydrous 2-propanol). The as-deposited perovskite films were subsequently thermally annealed at 150 8Cf or 10 min.…”

What defines the perovskite solar cell efficiency and stability: fullerene-based ETL structure or film morphology?

“…23 In another study, PC 61 BM was doped with hexamethonium bromide (HMB), which delivered PCE ∼18.0% in PSCs, that demonstrated a shelf life of >1100 h under an inert atmosphere without light. 24 Recently, Z. Xing et al have introduced a new set of pyrrolidinofullerene derivatives as ETLs in p–i–n PSCs and reported a PCE of 20%. 25 The designed ETLs enabled long-term ambient stability for ∼1056 h ( T 80 ) in air but without light illumination.…”