Nanoscale Characterization of Photocurrent and Photovoltage in Polycrystalline Solar Cells

Abstract

We investigate the role of grain structures in nanoscale carrier dynamics of polycrystalline solar cells. By using Kelvin probe force microscopy (KPFM) and near-field scanning photocurrent microscopy (NSPM) techniques, we characterize nanoscopic photovoltage and photocurrent patterns of inorganic CdTe and organic–inorganic hybrid perovskite solar cells. For CdTe solar cells, we analyze the nanoscale electric power patterns that are created by correlating nanoscale photovoltage and photocurrent maps on the same location. Distinct relations between the sample preparation conditions and the nanoscale photovoltaic properties of microscopic CdTe grain structures are observed. The same techniques are applied for characterization of a perovskite solar cell. It is found that a moderate amount of PbI2 near grain boundaries leads to the enhanced photogenerated carrier collections at grain boundaries. Finally, the capabilities and the limitations of the nanoscale techniques are discussed.

Pulsed Force Kelvin Probe Force Microscopy─A New Type of Kelvin Probe Force Microscopy under Ambient Conditions

“…As an available tool for chemical studies, KPFM, in general, provides a versatile tool for probing and understanding various aspects of material properties and behaviors at the nanoscale. One significant application is in surface potential mapping, where KPFM allows for precise delineation of surface potential variations, essential for deciphering surface charge distribution and electronic properties in semiconductor devices, catalysis, and energy materials, − as well as the emergence of charges due to frictionsthrough triboelectric charging . KPFM can also reveal surface modifications and provide insights into how surface alterations impact the electronic properties of materials, which is useful in the design of electronic devices, sensors, and catalysts. , Additionally, when coupled with electrochemical techniques, KPFM would enable the investigation of the transformation of electrode surfaces, , shedding light on the processes of degradation and modifications of the electrodes in batteries.…”

Carrier transport in bulk and two-dimensional Zn2(V,Nb,Ta)N3 ternary nitrides

“…6,7 The emergence of novel nanoscale materials, including nanocrystalline films, quantum dots and tandem multilayers of III–V materials, has led to the rise of the third generation of solar cells. 8–13 The next, fourth, generation of solar cells is based on inorganic nanocomponents, such as nanotubes, monolayers, and metal nanoparticles. 14–17 Therefore, there is still a wide range of materials to be tested or developed to discover the most functional ones for solar energy-based devices.…”

Scanning Photocurrent Microscopy in Single Crystal Multidimensional Hybrid Lead Bromide Perovskites

“…A versatile technique for studying the carriers’ generation and transport in semiconductors during the excitation is the use of a scanning confocal photocurrent microscopy (SCPM) [ 17 , 18 , 19 , 20 , 21 , 22 , 23 ], which allows the current generated in different regions of the sample by optical excitation to be mapped. Additionally, fluorescence information can be simultaneously acquired, which makes it possible to analyze the radiative processes of the samples being studied.…”