Browsing by Author "Chen, Chia-Yuan"

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Performance Characterization of Dye-Sensitized Photovoltaics under Indoor Lighting
(2017-04-20)
Chen, Chia-Yuan
;
Jian, Zih-Hong
;
Huang, Shih-Han
;
Lee, Kun-Mu
;
Kao, Ming-Hsuan
Indoor utilization of emerging photovoltaics is promising; however, efficiency characterization under room lighting is challenging. We report the first round-robin interlaboratory study of performance measurement for dye-sensitized photovoltaics (cells and mini-modules) and one silicon solar cell under a fluorescent dim light. Among 15 research groups, the relative deviation in power conversion efficiency (PCE) of the samples reaches an unprecedented 152%. On the basis of the comprehensive results, the gap between photometry and radiometry measurements and the response of devices to the dim illumination are identified as critical obstacles to the correct PCE. Therefore, we use an illuminometer as a prime standard with a spectroradiometer to quantify the intensity of indoor lighting and adopt the reverse-biased current voltage (I-V) characteristics as an indicator to qualify the I-V sampling time for dye-sensitized photovoltaics. The recommendations can brighten the prospects of emerging photovoltaics for indoor applications.
Thermal and angular dependence of next-generation photovoltaics under indoor lighting
(1970-01-01)
Chen, Chia-Yuan
;
Kuo, Ting-Yang
;
Huang, Chien-Wu
;
Jian, Zih-Hong
;
Hsiao, Po-Tsung
Next-generation photovoltaic technologies such as dye-sensitized solar cells, organic thin-film photovoltaics and perovskite solar cells are promising to efficiently harvest ambient light energy. However, more and deeper understanding of their photovoltaic characteristics is essential to create new applications under room light illumination. In this study, for the first time, the difference in temperature coefficients and angular dependence of photovoltaic parameters for the large-area devices are investigated systematically under the compact fluorescent lamp and light-emitting diode light. These emerging photovoltaic devices, compared with the single crystalline silicon solar cells, not only have higher open-circuit voltage (up to approximate 1 V) and better power conversion efficiency (in the range of 9.2% similar to 22.6%) but also exhibit less temperature dependent voltage and output power (< -0.6% degrees C-1), as well as broader angular response (over 75 degrees). The state-of-the-art dye-sensitized and organic thin-film devices also show advantageously positive temperature coefficients of current, and the latter even has positive thermal dependence of fill factor. These features suggest the next-generation photovoltaic devices are more favorable than the conventional crystalline silicon solar cells for real-life indoor applications.