CAJ | 학술논문

报道了自组装Si量子点(Si-QDs)阵列在室温下的共振隧穿及其微分负阻特性.在等离子增强化学气相沉淀系统中,采用layer-by-layer的淀积技术和原位等离子体氧化方法制备了Al/SiO2/Si-QDs/SiO2/Substrate双势垒结构.通过原子力显微镜和透射电子显微镜检测,证实所获得的Si-QDs阵列中Si量子点平均尺寸为6nm,并具有较好的尺寸均匀性(小于10%).在对样品的室温I-V和C-V特性的测量中,直接观测到由于Si量子点中分立能级而引起的共振隧穿和充电效应:I-V特性表现出显著的"微分负阻特性(NDR)";而CV特性中也同样观测到位置相对应、结构相似的峰结构,从而证实了I-V和C-V特性中的峰结构都同样来源于电子与Si量子点阵列中分离能级之间的共振隧穿和充电过程.进一步研究发现,Si量子点阵列中共振隧穿和NDR特性所特有"扫描方向"和"速率"依赖性及其机制,与量子阱的情况有所不同.通过所建立的主方程数值模型,成功地解释并重复了Si量子点阵中共振隧穿所特有的输运特性.
보도료자조장Si양자점(Si-QDs)진렬재실온하적공진수천급기미분부조특성.재등리자증강화학기상침정계통중,채용layer-by-layer적정적기술화원위등리자체양화방법제비료Al/SiO2/Si-QDs/SiO2/Substrate쌍세루결구.통과원자력현미경화투사전자현미경검측,증실소획득적Si-QDs진렬중Si양자점평균척촌위6nm,병구유교호적척촌균균성(소우10%).재대양품적실온I-V화C-V특성적측량중,직접관측도유우Si양자점중분립능급이인기적공진수천화충전효응:I-V특성표현출현저적"미분부조특성(NDR)";이CV특성중야동양관측도위치상대응、결구상사적봉결구,종이증실료I-V화C-V특성중적봉결구도동양래원우전자여Si양자점진렬중분리능급지간적공진수천화충전과정.진일보연구발현,Si양자점진렬중공진수천화NDR특성소특유"소묘방향"화"속솔"의뢰성급기궤제,여양자정적정황유소불동.통과소건립적주방정수치모형,성공지해석병중복료Si양자점진중공진수천소특유적수운특성.
We report the room temperature resonant tunneling and negative differential resistance (NDR) effects in a self-assembled Si quantum dot (Si-QDs) array. The double-layer structure of Al/SiO2/Si-QDs/SiO2/p-Si substrate is fabricated by layer-by-layer deposition and in situ plasma oxidation in a plasma-enhanced chemical vapor deposition (PECVD) system. Obvious NDR effects are directly observed in the current-voltage characteristics,and similar peak structures at the same voltage are also identified in the capacitance-voltage characteristics. Both of them are attributed to the resonant tunneling and charging dynamics in the Si-QD array. Moreover, the major features, such as the scan-rate and scan-direction dependences of the peak structure, are investigated, and the underlying mechanism is found to be quite different from that of a quantum well structure. Based on a master-equation numerical model,the resonant tunneling and charging dynamics together with the unique features can be satisfactorily explained and reproduced.