Perovskite Quantum-dot Floating-gates For Nonvolatile Organic Field-effect Transistor Memory And Artificial Synapse

In the era of"big data",the requirements for information storage capacity,speed,stability and other indicators are becoming higher,so we need better storage media to satisfy our higher demands.Non-volatile memory based on organic field effect transistors,due to the introduction of molecular design advantages of organic optoelectronic materials,can control the storage performance through molecular electronic structure,organic/inorganic doping,and so on.Therefore,it broadens the application scenarios of traditional silicon-based semiconductor memory,such as flexible storage,optical storage,etc.At the same time,artificial synapses based on organic field-effect transistor memories have also been research hotspots in recent years,which is attributed to its potentially application,such as memory-computing integrated chips and smart sensors.Therefore,the organic field effect transistor memory technology has attracted the attention of academia and industry.In this paper,we used perovskite quantum dots as the storage medium,and combined with organic electret PMMA to construct a hybrid floating gate type organic field effect transistor memory.Subsequently,we explored the effect of perovskite quantum dots'crystal morphology effect on storage performance,and finally applied it to the development of bionic synaptic devices.The main research contents are as follows:1. We studied the crystal growth of CsPbBr₃ QDs thin films under different solvents,and compared the electrical characteristics of morphology-induced organic field effect transistor memories.It was found that when n-hexane was used as the solvent,a discontinuous large-scale crystal morphology could be formed.The memory device exhibits bipolar storage characteristics,with a storage window of 28 V at a write voltage of±40.0 V.2. We studied the storage characteristics of organic field effect transistor memories with CsPbBr₃ QDs,CsPbCl₃ QDs,and Cs Pb I₃ QDs as nanofloating gate storage media.The results show that at the same solution concentration,halogen ions will change the crystal growth morphology of the storage layer.The CsPbCl₃ QDs device has the strongest hole-trapping ability,the CsPbBr₃ QDs device has the strongest electron-trapping ability,and the electrons of the three quantum dot devices The trapping ability is better than its hole trapping ability.3. On the basis of the above work,we chose CsPbBr₃ QDs with the strongest bipolar charge storage capacity to prepare transistor synapse devices based on pentacene semiconductor layers.The device can realize basic synaptic function simulation,such as enhancement-suppression characteristics,Steady-state plasticity,etc.The results show that the applied gate voltage and the concentration of CsPbBr₃ QDs can adjust the plastic properties of the synaptic device.