Tunable bandgap in hybrid perovskite CH3NH3Pb(Br3−yXy) single crystals and photodetector applications

L Wang,R F Duan,J M Li,J X Wang,T B Wei,Z Q Liu,G D Yuan,F Huang

doi:10.1063/1.4948312

L Wang, R F Duan + Show 6 more

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https://doi.org/10.1063/1.4948312

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Abstract

We report the synthesis of CH3NH3Pb(Br3−yXy) (X=Cl and I) single crystals via a stepwise temperature control approach. High-quality CH3NH3Pb(Br3−yXy) crystals with a tunable bandgap from 1.92eV to 2.53eV have been prepared successfully in this way. And further experiments revealed the influence of halogen content and preparation temperature on the structural and optical properties of these crystals. It is observed that chlorine can lower the critical nucleation energy, which results in crystallizing at lower temperature with the chlorine content increasing, while the nucleation energy increases slowly with increasing iodine content. Moreover, in contrast to Frank–van der Merwe growth with low heating rate, high heating rate leads to a mass of small size single crystals and Stranski-Krastanov growth. The single crystals with tunable band gap and impressive characteristics enable us to fabricate high performance photodetectors for different wavelengths.

Highlights

INTRODUCTIONThe introduction of organometallic halide perovskites (especially CH3NH3PbX3, MAPbX3, X =Cl, Br or I) is triggering a quasi-revolution in the field of solar cells
The introduction of organometallic halide perovskites is triggering a quasi-revolution in the field of solar cells
We report the synthesis of CH3NH3Pb(Br3−yXy) (X=Cl and I) single crystals via a stepwise temperature control approach

Summary

INTRODUCTION

The introduction of organometallic halide perovskites (especially CH3NH3PbX3, MAPbX3, X =Cl, Br or I) is triggering a quasi-revolution in the field of solar cells Due to their high absorption, long balanced carrier diffusion length, tunable energy gap, and low cost, the organometallic halide perovskites have attracted many researchers’ attention.[1,2,3,4] Over the last decade, the organometallic halide perovskites based semiconductor devices, especially the perovskite solar cells, have developed dramatically. Based on as-synthesized perovskite single crystals, we fabricated metal-semiconductor-metal (MSM) photodetectors, which have shown a high ON/OFF ratio and a high switch speed

EXPERIMENTS

RESULTS AND DISCUSSION

CONCLUSIONS