상세정보

The tin halide perovskite solar cells (THPSCs) have attracted in photovoltaic field, which is a promising candiate to address the concerns about potential lead toxicity and theoretical efficiency limit of lead halide perovskite photovoltaics. Nevertheless, THPSCs suffer from the severe oxidation from Sn2+ to Sn4+ and fast crystallization, leading to the low performance of devices. In this work, we incorporate the bromide in composition engineering, which occured 2D/3D hybrid cations tin halide perovskite films with high oriented crystallization and surppressed oxidation. Furthermore, we investigate the computational quantum mechanical modelling method to find the clue of the high stability against the oxygen and how to incorporating the bromide can lowering the trap density. We succeed in improving the crystallinity of 2D/3D hybrid perovskite by highly oriented surface to bulk direction. This leads to decrease of traps and charge recommbination losses in the device. Consequently, devices using X = 0.30 bromide in the perovskite layer with composition PEA15EA15FA70SnI3-XBrX  shown 8.47% of power conversion efficiency by suppressed Sn4+ oxidation state, improved vertical orientation of the perovskite and good band alignment. Moreover, maintained over 80% of original efficiency after 80min storage under light soaking with encapsulation.

Contents
Abstract ............................................................................... Ⅰ
Abstract (in Korean; 국문요약) ..................................... Ⅱ
List of Figure ..................................................................... Ⅲ
List of Tables ..................................................................... Ⅵ
1. Introduction ................................................................................ 1
1.1 Perovskite solar cells ............................................................ 3
1.2 Lead free perovskite solar cells ........................................... 4
1.3 Tin-based perovskite solar cells .......................................... 5
1.3.1 2D and quasi-2D tin perovskite .................................. 6
1.3.2 X site compositional engineering ................................ 7
2. Materials and Methods .............................................................. 9
2.1 Materials ................................................................................ 9
2.2 Experimental method ........................................................... 9
2.2.1 Device design .............................................................. 9
2.2.2 Device fabrication .................................................... 10
2.2.3 Characterization .................................................... 11
2.2.4 Computational Methods ....................................... 13
3. Results and discussion ............................................................. 14
3.1 Device structure .................................................................. 14
3.2 Morphology of the perovskite films .................................. 17
3.3 Optoelectronic property of the perovskite films .............. 27
3.4 Device Performance............................................................ 39
3.5 Computational quantum mechanical modelling ........... 46
4. Conclusion ................................................................................ 54
5. Reference................................................................................... 55