Si Radial Junction And It'S Application In Photoelectric Cardiac Sitimulators And Red/Green/Blue Colour Sensors

Silicon is earth's most common,but also extremely valuable element.Since World War 2,silicon has been widely used in the electrical engineering industry.As science and technology advanced,silicon has become the indispensable element to the modern electrical engineering industry.From solar panels to circuit boards,from CPU chip to DRAM,the application of silicon semiconductors has spread across the whole industrial chain.Various production technologies of silicon have matured thanks to the progress in the field during the past half century.However,the development of silicon semiconductors has reached its bottleneck in recent years.First,the technology related to this material has almost reached its full potential.Secondly,so many manufacturers have to invest exponentially growing fund in order to compete on the market,which leads to diminishing profit margin.Our lab has plenty of experience with amorphous silicon radial tandem junction photovoltaic device and has made some attempts in application.We worked with the National Center of Cardiovascular Diseases and the Fuwai Hospital to study the application of radial junction in photoelectric cardiac stimulators.Implanted pacemakers send electric signals to human heart to maintain the regularity of the heartbeat.Clinical existing pacemakers are usually voluminous and made of hard materials.Moreover,battery life span requires additional surgery to change battery,leading to pain,risk of secondary infection and extra costs.Our self?powered photoelectric cardiac stimulator,on the other side,can: 1.Generate electric signals by itself under illumination.The voltage,current and frequency of the signal can all be moderated from the power and frequency of the light source.2.The silicon material is non-toxic and bio-compatible and biodegradable,with huge potential in bio-applications.3.The flexible radial junction stimulators can be conformally attached to the uneven tissue surface to pace heartbeat.4.In vivo pacing experiments on porcine hearts show that the heart rate can be successfully controlled by the PINIP nanowires patch.This implantable PINIP radial junction cardiac photoelectric unit is self?powered,biocompatible,and conformable.It has the potential to be widely used as a cardiac pacing technology,in the future clinical treatment.We gain insights from the 3D structure of human photoreceptor cells.The human cone and rod cells are densely packed on the retina and follows a forest-like distribution which is beneficial to the absorption of light.Vertical radial junction nanowire shares a similar pattern.Due to the size of those nanowires,there is cavity mode inside of the nanowire which allows light with different wavelength to be absorbed in different regions.According to our analysis,the PINIP structure along with controlled external voltage bias can selectively collect photo-generated carriers in different regions.Subsequent experiments prove that this device can produce similar RGB response compared to the human cone cell.Based on these observations,we created an RGB sensor using the PINIP radial tandem junction nanowire.The novelties of this sensor are the following: 1.Controllable spectrum response with applied voltage bias.2.Filter free which is beneficial for high resolution imaging.3.Can detect the RGB components in a certain light,similar to the operational principle of human cone cells.4.Using stateof-the-art pattern recognition techniques to improve the accuracy.