Synthesis and characterization of InP quantum dots for photovoltaics applications

Abstract

In this article, InP quantum dots (QDs) are synthesized with a green methodology. The preparation of the InP QDs is demonstrated by varying the ratios of the precursors used such as InCl3 and trioctylphosphine (TOP). These QDs are fabricated through the application of TOP (as phosphorous source and reducing agent for the In salt) for forming indium and to develop the targeted InP QDs, which are characterized using HRTEM, XRD, PL, FTIR, UV–Vis, and time resolved spectroscopy. A rapid reaction time (~ 30 min) procedure in a single pot at a temperature of ~ 310 °C is developed. InP QDs with particle sizes varying from 4 to 6 nm have been measured with different concentrations of InCl3 and TOP. InP QDs yield reached 23%. Zincblende crystal structure is recognized for InP with high orientation plane of (220) as confirmed with XRD and confirmed with SAED. Solar cell devices are built by anchoring the InP QDs onto a TiO2 layer and measure the photovoltaic performance and spectral response of the device built on FTO/glass substrate. TiO2/InP QDs solar cell devices are fabricated with high fill factor of 0.86 and open circuit voltage value of 501 mV and overall efficiency of 0.48%.

Theoretical Investigation of Organic Ligands on the Surface Structure of InP Quantum Dots: Implications for Display Materials with Enhanced Surface Stability

“…When synthesizing InP QDs, tris­(trimethylsilyl)­phosphine (TMS 3 P) is used as a representative P-source by mixing it with the TOP. − During synthesis, TMS 3 P is expected to readily decompose, making it unclear whether it binds to the surface of the final QD and if so, in what form. However, it is known that TOP binds to the InP QD surface even though its surface binding characteristics have not been extensively studied. − In this study, the surface stabilization through binding of TOP was investigated using TMS that mimics phosphine ligands. To construct the ligated surface, one side of the surface is passivated with the organic ligands, while the other side is passivated with pseudo hydrogen atoms.…”