Noise and Scanning by Local Illumination as Reliability Estimation for Silicon Solar Cells

Abstract

This paper presents two methods, namely those using noise and homogeneity measurements of a large area solar cells, for determining the local defects, which bring down efficiency and long reliability of single-crystal silicon solar cells. As a result of the non-uniformities (non-homogeneity) in the large junction area, local areas with lower built-in potentials at the junction lead to hot spots and reduced reliability. The two techniques can be used to give a precise description of the quality of the product technology. Correlations between noise and inhomogeneities for an ensemble of 30 silicon solar cell samples are given.

Low-frequency noise measurements used for semiconductors light active devices

“…The constant is quite ideally equal to 1 and is quite equal to 2 (for commercial silicon a solar cell, the value little deviates from the theoretically assumed value of 2) It is known that most failures result from latent defects created during the manufacture process or during the operating life of the devices [6]. The sensitivity of excess electrical noise to this kind of defects is the main reason for investigating and using noise as a diagnostic and prediction tool in reliability physics for the semiconductor device lifetime assessment [4,12]. The noise spectral density depends on the applied stress and induced damage and varies among nominally identical devices.…”

Digital noise spectroscopy system and its application to solar cells

“…Since then, there have been two major trends. The fIrst is to measure more noise spectra, initially by use of analog instrumentation [6]. The second and more recent advance is the use of digital tools to obtain noise spectra [7].…”

Influence of noise shape on excitation kinetics of impurity doped quantum dots

“…The notable applications include industrial manufacturing, medicine, remote sensing, space communications, and military uses [41], to mention a few. Such noise measurements are also becoming useful as a pretty innocuous method for the determination of structural disorders entered during production or operation of the devices [42,43]. The extent of stress suffered by QD during its growth produces lattice defects which diffuse through the QD structure.…”

“…The said low-frequency noise also provides a diagnostic tool for defect related properties of materials and structures [44]. Chabola and Ibrahim have extensively studied the role of lowfrequency noise in non-homogeneously doped semiconductors [42]. Of late we have made some investigations on excitation kinetics of doped QD induced by noise [45].…”