Study of Nano-Scale Electrical Properties of Hydrogenated Microcrystalline Silicon Solar Cells by Conductive Atomic Force Microscope

摘要

The nano-scale current-voltage (Ⅰ-Ⅴ) characteristics of hydrogenated microcrystalline silicon (μc-Si:H) solar cells were studied by conductive atomic force microscope (conductive AFM) for the first time. A large local reverse (leakage) current was observed at a grain boundary, which was measured during the detection of the surface topography of a μc-Si:H solar cell in the contact mode. The grain boundary of the μc-Si:H solar cell might behave similarly to a current leakage path. In conductive AFM measurement, we found that surface topography of the μc-Si:H solar cell is composed of large convex regions. Here, a large convex region is formed by the aggregation of small grains with a diameter of ～20 nm, which is similar to that of a silicon nanocrystallite determined by X-ray diffraction (XRD) measurement. We successfully evaluated the relationship between the nano-scale electrical properties and characteristics of grain boundaries. The obtained result indicates that the nano-scale quality of the μc-Si:H solar cell can be characterized by conductive AFM with a high experimental resolution of ～1nm.