Organometal Halide Perovskite (OMHP) based Solar Cells (SC) have recently experienced an intensive research due to their low cost and high efficiency.^1,2 In particular, the OMHP presents very attractive characteristics such as superior charge transport properties with a long-range ambipolar behaviour, low exciton binding energy or magnetic field effects.^3,4 One important motivation of researchers is the fundamental understanding of OMHP since many aspects around fundamental physics governing device operation are still under debate and needs to be unravelled to understand and optimize its behaviour.³

The microstructure is a crucial aspect which governs the optoelectronic properties of OMHP materials.^5,6 Many examples can be found in literature of OMHP with different microstructures such as layered structures or micro and nanocrystals.^5,6 But only few examples can be found in literature about their one dimensional(1D) structuration, which is foreseen to have a crucial impact on many aspects of SC performance such as efficiency, absorption of light or antireflection capabilities.^7,8 The demonstration that 1D nanostructures represents a feasible technology for future photovoltaics requires suitable synthesis methods to fabricate the required multilayer architecture in one-dimension and a direct comparison with its two dimensional analogue for their fundamental understanding.

Nowadays, most of OMHP devices are fabricated via wet methods and thus the interfaces are exposed to liquids, water or environmental gases. For example, perovskites are usually deposited under nitrogen atmosphere to avoid hydrolysis⁹ that leads to an important deterioration of the SC performance and therefore should be avoided. The improvement of crucial aspects of the cells such as efficiency or durability requires a clean and dry approach to avoid the exposition of the relevant interfaces to the atmosphere.

In this work we report a full vacuum methodology to develop one-dimensional OMHP nanostructures. A full microstructural, optical and luminescence characterization is presented which shows the optoelectronic modifications induced by the microstructure. This work demonstrates the feasibility of the approach and paves the way for the fabrication of highly efficient one-dimensional OMPH solar cells.

(1)           Green, M. A.; et al. Nat. Photonics 2014, 8(7), 506.

(2)           Ye, M.; et al. J. Mater. Chem. A 2016, 4(18), 6755.

(3)           Leong, W. L.; et al. Adv. Mater. 2016, 28(12), 2439.

(4)           Hsiao, Y.-C.; et al. J. Mater Chem A 2015, 3(30), 15372.

(5)           Fang, H.-H.; et al. Adv. Funct. Mater. 2015, 25(16), 2378.

(6)           Bai, S.; et al. J Mater Chem C 2016, 4(18), 3898.

(7)           He, M.; et al. J. Mater. Chem. A 2014, 2(17), 5994.

(8)           Yu, M.; et al. Nanoscale 2012, 4(9), 2783.

(9)           Stoumpos, C. C.; et al. Inorg. Chem.2013, 52(15), 9019.