The Effect Of The Interface Between The Multi-semiconductor On The Electrical Properties Of Transistor And Its Mechanism

In Silicon-based electronics,doping is the main and effective method to modulate theperformance of the devices.But this method can not be used in some newly-developing application,such as nanoelectronics,organic electronics.Hence,introducing interface provides a simple but effective approach toward creating high-performance devices.The interface between the multi-layer semiconductors can be divided into two types:point-contact?between single crystals?and surface-contact?between films?.Based on field-effect transistor,we constructed the crossed nanowire by a simple mechanical manipulation method,and investigated the modulation on electrical properties for pint-sized and multi-functional application.In addition,selecting functional semiconductor as the buffer layer not only can enhance the performance of FETs,but also increase the application in multi-field.In our experiments,based on field-effect transistor,we have investigated the effect of the interface between the nanowires and films on the electrical properties of FETs,respectively.The main results are as follows:1.The transport properties and mechanism of the three-terminal field-effect nanowire cross junction have been systematically investigated based on SnO₂ nanowires.An interesting phenomenon has been observed that applied voltage bias on nanowire cross junction makes the ON/OFF current ratio of the transistor improved by over 2 orders of magnitude?10⁷?10⁹?.Different from the two-terminal nanowire cross junctions,the cross junction induced potential barrier in three-terminal counterparts is found to be capable to prevent the current of the top semiconductor nanowire from injecting into the bottom nanowire at off state,while to make the current of the top semiconductor nanowire contribute to the current of the bottom nanowire at on state,resulting in the current switch between on state and off state by gate voltage modulation.2.Using F₁₆CuPc and SnO₂ as top crossed semiconductor nanowires,we show how the carrier concentration in crossed top nanowire affects the electrical properties of F₁₆CuPc nanowire.Only the crossed SnO2 nanowire can be used to modulate the on-state current of the F₁₆CuPc nanowire transistor and to remain off-state current unchanged.The semiconductor step introduced by crossed nanowire is a fatal effect on F16CuPc organic-organic crossed nanowire transistor.Our experiment results explain the previously reported degraded performance in organic nanowire crossed network,and provide a potential for organic-inorganic crossed nanowire hybrid in future multi-functional applications.To verify the experiment result,we used high carrier concentration rubrene to form crossed nanobelts and observed the same modulated phenomenon on Ion/Ioffby over 2 orders of magnitude?10⁷?10⁹?.Highly ordered structure and the absence of grain boundary defects in organic single crystals are favorable for high mobility,while they dramatically improve the off-state current and hence lower I_on/I_off.Our results show that crossed nanowire structure is a simple way to improve I_on/I_off of organic single crystal transistor.3.We selected emitting materials as buffer layer between the n-type and p-type films.In our experiments,it can obtain balanced n-type and p-type mobilites which result the better performance of ambipolar transistor and increase the photoelectric properties.By using the optical or electrical as the input signals,the difference combination of the ambipolar transistor can achieve basic logic gate,such as NOT,OR,and NOR.Such optoelectronic circuits could be explored in various applications including electro-optical transceivers and optical sensor arrays in future.