Naphthalene Diimide Ammonium Directed Single-Crystalline Perovskites with “Atypical” Ambipolar Charge Transport Signatures in Two-Dimensional Limit

Abstract

A single crystal of a lead−iodine-based 2D perovskite having naphthalene diimide ammonium (NDIA) molecules as organic layers was developed, and the charge transport property was studied using field-effect transistors (FETs) measurements. Structure determination reveals the layered alternative stacking of lead iodide sheets and NDIA bilayers. The presence of NDIA promoted the lead iodide octahedron to form the unique three-point co-planar [Pb 3 I 10 ] 4− unit, which then connected into the 2D network in a corner-sharing manner. The NDIA cations closely stacked into 1D chains within the bilayers that were being sandwiched between the inorganic layers. FET characteristics of the single crystal obtained at room temperature demonstrate V DS -dependent electron and hole transport behavior with mobilities reaching up to more than 5 × 10 −3 cm 2 V −1 s −1 . The 1D stack of NDIAs contributes greatly to the performance improvement for both the charge transport and the stability.

Charge Transport in 2D Layered Mixed Sn–Pb Perovskite Thin Films for Field‐Effect Transistors

“…Although the device performance is reduced with the decrease of the electronic conductivity as the Pb content increases with respect to the pure Sn perovskite transistor because of the above similar reasons discussed for the (PEA) 2 PbI 4 transistor, as shown in Figure 4h, the best performance is achieved in the (PEA) 2 Sn 0.7 Pb 0.3 I 4 device that exhibits a hole mobility of 0.02 cm 2 V −1 s −1 and a threshold voltage of 8 V. To the best of our knowledge, this mobility represents the highest value that has been achieved in 2D layered Pb‐containing perovskite field‐effect transistors at room temperature in air since only SiO 2 ‐gated ambipolar naphthalene diimide ammonium ((NDIA) 4 Pb 3 I 10 ) perovskite crystal field‐effect transistors with balanced hole and electron mobilities of 5 × 10 −3 cm 2 V −1 s −1[ 11a ] and n‐type ((BA) 2 (MA) n −1 Pb n I 3 n +1 ) ( n = 1, 2, 3, 4, 5) single crystal transistors operating at temperatures below 160 K have been reported. [ 3c,11b,c ] The enhanced carrier transport in the channel due to its good crystallization and big grain size as well as the minimum injection barrier and weak ion migration contribute to the good performance in this (PEA) 2 Sn 0.7 Pb 0.3 I 4 transistor. In particular, owing to the reduced the source–drain current at zero gate bias, an on‐to‐off current ratio of 100 is realized in this device.…”

“…[ 5 ] The most common 2D layered perovskite materials currently used in transistors are Sn‐based perovskites, such as phenylethylammonium tin iodide perovskite ((PEA) 2 SnI 4 ) and its derivatives, [ 6 ] 2‐(3′″,4′‐dimethyl‐[2,2′:5′,2″:5″,2′″‐quaterthiophen]‐5‐yl)ethan‐1‐ammonium tin perovskite ((4TM) 2 SnI 4 ), [ 7 ] butylammonium tin iodide perovskite ( n ‐BA 2 SnI 4 ), [ 8 ] (PEA) 2 (FA) n −1 Sn n I 3 n +1 ( n = 4, 8; FA: formamidinium), [ 9 ] and (PEA) 2 CsSn 2 I 7 (Cs: cesium), [ 10 ] while very few studies have been focused on 2D Pb‐based perovskite field‐effect transistors. [ 3c,11 ] Among them, (PEA) 2 SnI 4 is the first hybrid perovskite material applied to transistors, [ 6a ] and a record‐breaking hole mobility of 15 cm 2 V −1 s −1 has been achieved in the (PEA) 2 SnI 4 field‐effect transistors in vacuum at room temperature. [ 6d ] Nevertheless, it is well‐known that Sn 2+ is easily oxidized to Sn 4+ , giving rise to harmful p‐type self‐doping, which increases the conductivity of Sn‐based perovskites and causes accumulation–depletion mode in the resulting transistors.…”

Recent Advances in Ambipolar Transistors for Functional Applications

“…In addition to traditional layered 2D materials (e.g., graphene, TMDs, h‐BN, and BP), 2D organic systems and 2D perovskites also attract lots of attention . For example, 2D perovskites based on naphthalene diimide ammonium (NDIA) and lead halide ((NDIA) 4 Pb 3 I 10 ) were demonstrated to show drain voltage–dependent charge transport behaviors . Although both electrical performance and stability were improved, the charge mobility was still inferior.…”

“…These semiconductors possess a favorable direct bandgap of 1.5–1.65 eV and a good absorption coefficient. Thus, OIHPMs are extremely promising to be utilized in ambipolar transistors …”

Halogen-Manipulated Interfacial Charge Transport of π-Conjugated Molecule-Lead Halide Hybrids

“…An investigation of a series of layered perovskites, where naphthalene, pyrene, or perylene was cooperated as the aromatic linker, has revealed enhanced out-of-plane conductivity whose energy levels match better those of the PbI 4 inorganic layers . By introducing a naphthalene diimide ammonium (NDIA) molecule, we have constructed a single crystal of 2D perovskite semiconductor which demonstrated superior ambipolar charge transport signatures . Nevertheless, the way of the organic semiconductor molecules in manipulating the charge transport within the OIHPs lattice remains controversial.…”