This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Fabrication of organic solar array for applications in microelectromechanical systems Jason Lewis, Jian Zhang, and Xiaomei Jiang a ! Department of Physics, University of South Florida, Tampa, Florida 33620, USA s Received 11 August 2008; accepted 11 September 2008; published online 6 November 2008 d We have developed an innovative way to fabricate organic solar arrays for appli- cation in dc power supplies for electrostatic microelectromechanical systems de- vices. A solar array with 20 miniature cells interconnected in series was fabricated and characterized. Photolithography was used to isolate the individual cells and output contacts of the array, whereas the thermal-vacuum deposition is employed to make the series connections of the array. With 1 mm 2 for single cell and a total device area of 2.2 cm 2 , the organic solar array based on bulk heterojunction struc- ture of p-conjugated polymers and C 60 derivative f 6,6 g-phenyl C 61 butyric acid methyl ester produced an open-circuit voltage of 7.8 V and a short-circuit current of 55 m A under simulated air mass s AM d 1.5 illumination with an intensity of 132 mW / cm 2 . The procedure described here has the full potential for use in future fabrication of microarray with the size as small as 0.01 mm 2 . © 2009 American Institute of Physics. f DOI: 10.1063/1.2998825 g I. INTRODUCTION Microelectromechanical systems s MEMS d usually have their own requirements for power supplies. It is desirable to have appropriate on-chip power source with the MEMS device, par- ticularly in cases of autonomous operations such as wireless communication, sensor network, and microrobotic systems. Previous solutions for such power supplies include magnetic field induced current and voltage supplies, 1 electrothermal microactuators based on dielectric loss heating, 2 rechargable lithium microbatteries, 3 integrated thermopile structures, 4 vibration-electric energy conversion, 5 and miniature fuel cells. 6 Solar cell can also be a good option for such power sources since it is self-contained and can be easily integrated with existing circuits of MEMS. Moreover, solar cell has the potential of achieving the maximum size to power density ratio compared with other miniature power sources. 7 There have been previous studies about on-chip solar cell arrays for applications in MEMS devices, 7 – 11 and the majority of these works have been related to the silicon photovoltaic cells. Organic solar cells s OSC d based on p-conjugated polymers f e.g., poly-3-hexylthiophene s P3HT dg and fullerene derivatives f e.g., s 6,6 d-phenyl C 61 butyric acid methyl ester s PCBM dg have attracted attention over the past decades because they may provide a cost-effective route to wide use of solar energy for electrical power generation....
View Full Document
- Spring '11