Solar Cell Evaluation Device Spectral Responsivity Calibration
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Solution Overview
Problem
Existing solar cell evaluation methods require a reference cell for calibration, which is time-consuming and costly, and are inaccurate for solar cells with spectral responsivity that changes with light quantity, such as thin film and organic cells.
Innovation Solution
A light source evaluation device that measures the spectral responsivity of a solar cell at various irradiance levels and adjusts the light quantity of the solar simulator using pre-measured spectral responsivity data and reference sunlight spectral irradiance to accurately match the reference sunlight conditions without a reference cell.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a reference cell is used for calibration of solar simulator, then measurement accuracy can be improved, but calibration time and cost increase significantly
Solution Approach 1:
The patent uses a spectral irradiance measurement device to measure the actual spectral irradiance of the solar simulator and creates a digital copy of this spectrum. This measured spectral data is then used for calibration calculations, replacing the need for physical reference cell calibration while maintaining measurement accuracy.
Solution Approach 2:
The patent replaces the mechanical/physical calibration process using reference cells with an optical measurement and computational system. A spectral irradiance measurement device measures the light spectrum, and a computer processes this data to determine calibration factors, eliminating the need for physical reference cell handling and calibration procedures.
2Loss of time
If spectral irradiance measurement and calculation method is used, then calibration time can be reduced, but measurement accuracy for solar cells with non-linear characteristics may deteriorate
Solution Approach 1:
The patent incorporates feedback mechanisms where the measured spectral irradiance data is used to calculate calibration factors, which are then applied to adjust the solar simulator output. This feedback loop ensures that the calibration accurately reflects the actual spectral conditions, maintaining measurement accuracy for non-linear solar cells while reducing calibration time.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables precise adjustment of light quantity for solar cells with varying spectral responsivity, reducing calibration time and cost, and allowing for accurate evaluation of solar cells with non-linear characteristics.
Implementation Method 1
a spectro-radiometer that measures a spectral irradiance L(λ) of a light source for illuminating a measurement target solar cell
Implementation Method 2
a dependency P(λ, Ib) for each wavelength of a short-circuit current Ib generated by white bias light of a measurement target solar cell
Data Source
AI summary
With a light source evaluation device 10 according to the present invention and a solar cell evaluation device 1 employing the same, a dependency P (λ, Ib) for each wavelength λ of a short-circuit current Ib generated by white bias light of a measurement target solar cell 2, which is pre-measured at each of a plurality (i) of irradiance levels, is regarded as a spectral responsivity Pi (λ) at each irradiance level, and a value for adjusting a light quantity of an illumination light source 3 that illuminates the solar cell 2 is computed using a spectral responsivity Ps (λ), which is computed using the spectral responsivity Pi (λ), a pre-supplied spectral irradiance S (λ) of reference sunlight, and a pre-measured spectral irradiance L (λ) of the illumination light source 3. Therefore the light source evaluation device 10 having this configuration and the solar cell evaluation device 1 employing the same can accurately adjust the light quantity of the illumination light source 3 when evaluating the solar cell 2 of which spectral responsivity changes depending on the light quantity.