From Lead Iodide to a Radical Form Lead‐Iodide Superlattice: High Conductance Gain and Broader Band for Photoconductive Response

Abstract

Superlattice materials offer new opportunities to modify optical and electrical properties of recently emerging 2D materials.T he insertion of tetraethylbenzidine (EtDAB) into interlamination of the established 2D PbI 2 semiconductor through am ild solution method yielded the first lead iodide superlattice,E tDAB·4PbI 2 (EtDAB = tetraethylbenzidine), with radical and non-radical forms.T he non-radical form has an on-ionic structure that differs from the common ionic structures for inorganic-organic hybrid lead halides.T he radical form shows five orders of magnitude greater conductance and broader photoconductive response range (UV/Vis ! UV/Vis-IR), than pure PbI 2 and the non-radical form of the superlattice.

Directed self-assembly of viologen-based 2D semiconductors with intrinsic UV–SWIR photoresponse after photo/thermo activation

“…However, practical application of them is still greatly limited by material rigidity, as well as complex and expensive manufacturing processes 14,15 . Organic-based photoelectronic semiconductors are characteristic of flexibility and facile preparation, but the observed up limit for photoresponse is about 1800 nm 10,12,[15][16][17][18] . It is still of importance to develop effective and general design methods for single-component organic-based semiconductors with intrinsic photoresponse in the entire UV-SWIR range.…”

Liquid Exfoliation of Two-Dimensional PbI2 Nanosheets for Ultrafast Photonics

“…As shown in Figure 1a and b, PbI 2 has a canonical layered structure with covalently bonded I−Pb−I repeating units with a separation of 6.98 Å governed by weak van der Waals interactions. 20 After being subjected to mild bath ultrasonication followed by centrifugation (CF) (to remove poorly exfoliated aggregates), stable fewlayer PbI 2 dispersions were readily obtained in the polar aprotic solvent (CH 2 ) 4 CO. The Tyndall effect of the dispersion indicates its colloidal nature (Figure 1c).…”

Superlattices based on van der Waals 2D materials

“…Optoelectronics [55][56][57][58][59][60][61][72][73][74][75] Superconductivity 62 Thermoelectrics 63,64 Energy storage [67][68][69][70][71] Moiré periodic patterns Atom rearrangement, misorientation angle, strain (2D)…”

“…57 The tuning of the electrical and optical properties through intercalation has been also observed in ammonia ions-WS 2 host, 58 lithium ions-NbSe 2 host, 59 cetyltrimethylammonium bromide (CTAB) in black phosphorus (BP), 60 and tetraethylbenzidine (EtDAB) ions in PbI 2 . 61 In a recent work, the coexistence of superconductivity and ferromagnetism originated from non-superconducting and non-ferromagnetic components has been achieved by the fabrication of a twodimensional SnSe 2 /Co(Cp) 2 superlattice, where Cp represents cyclopentadienyl molecules. A TEM cross-section of the superlattice is shown in Fig.…”