Charge Transport and Photoconductivity in a Hybrid Uranium(IV) Halide Perovskite

Abstract

Hybrid metal halide perovskites are extensively synthesized using p-and d-elements. However, the properties of hybrid halide perovskites involving 5f-elements are still elusive. Herein, we first report the semiconductive property of a uraniumbearing hybrid halide perovskite, [N(C 2 H 5 ) 4 ] 2 UCl 6 (EAUCl). Single crystal X-ray crystallography demonstrates that EAUCl adopts a zero-dimensional molecular structure consisting of isolated [UCl 6 ] 2− anions and organic cations. The intrinsically semiconductive property endows EAUCl with obvious charge transport and photoconductivity, with a high carrier mobility lifetime (μτ) product of 9.91 × 10 −4 cm 2 /V and a photocurrent on−off ratio of 380 under X-ray excitation. Theoretical calculations corroborate that the U 5f orbitals are involved in electron transitions and the formation of band structure.

Semiconductive Behavior and Photoconductivity of Uranyl Dithiophosphinate Single Crystal

“…The leakage current of the device was measured at a level of 10 −10 A when testing the sample in a dark field without X-rays under an applied bias voltage ranging from −30 to 30 V. The resistivity of the sample was calculated to be 2.797 × 10 9 Ω•cm, which confirms the examination requirement for conventional semiconductors for X-ray detection. 29 Compared with its dark counterpart, U-DPDPP exhibited a significant response to X-ray excitation, as demonstrated in Figure 3a, with the current increasing by 2 orders of magnitude. It is suggested that there is significant charge carrier generation and charge transport in U-DPDPP under Xray irradiation.…”

“…A single-crystal sample (1.2 mm × 1.1 mm × 0.9 mm) was affixed to a small circuit board using conductive silver adhesive and copper wire for X-ray irradiation. The leakage current of the device was measured at a level of 10 –10 A when testing the sample in a dark field without X-rays under an applied bias voltage ranging from −30 to 30 V. The resistivity of the sample was calculated to be 2.797 × 10 9 Ω·cm, which confirms the examination requirement for conventional semiconductors for X-ray detection …”