Laboratoire de Photonique et de Nanostructures, CNRS UPR20, Université Paris-Saclay, Route de Nozay, F-91460 Marcoussis, France.
Nanotechnology. 2016 Aug 12;27(32):325403. doi: 10.1088/0957-4484/27/32/325403. Epub 2016 Jul 1.
We demonstrate the first piezo-generator integrating a vertical array of GaN nanowires (NWs). We perform a systematic multi-scale analysis, going from single wire properties to macroscopic device fabrication and characterization, which allows us to establish for GaN NWs the relationship between the material properties and the piezo-generation, and to propose an efficient piezo-generator design. The piezo-conversion of individual MBE-grown p-doped GaN NWs in a dense array is assessed by atomic force microscopy (AFM) equipped with a Resiscope module yielding an average output voltage of 228 ± 120 mV and a maximum value of 350 mV generated per NW. In the case of p-doped GaN NWs, the piezo-generation is achieved when a positive piezo-potential is created inside the nanostructures, i.e. when the NWs are submitted to compressive deformation. The understanding of the piezo-generation mechanism in our GaN NWs, gained from AFM analyses, is applied to design a piezo-generator operated under compressive strain. The device consists of NW arrays of several square millimeters in size embedded into spin-on glass with a Schottky contact for rectification and collection of piezo-generated carriers. The generator delivers a maximum power density of ∼12.7 mW cm(-3). This value sets the new state of the art for piezo-generators based on GaN NWs and more generally on nitride NWs, and offers promising prospects for the use of GaN NWs as high-efficiency ultra-compact energy harvesters.
我们展示了第一个集成了垂直 GaN 纳米线（NWs）阵列的压电发电机。我们进行了系统的多尺度分析，从单根线的性能到宏观器件的制造和表征，这使我们能够确定 GaN NWs 的材料性能与压电产生之间的关系，并提出了一种有效的压电发电机设计。通过配备 Resiscope 模块的原子力显微镜（AFM）评估了在密集阵列中生长的 MBE 掺杂 p 型 GaN NW 的单个 NW 的压电转换，平均输出电压为 228 ± 120 mV，最大值为 350 mV 每个 NW 产生。对于 p 型 GaN NWs，当在纳米结构内部产生正压电电势时，即当 NWs受到压缩变形时，实现了压电产生。通过 AFM 分析获得的对我们 GaN NWs 中压电产生机制的理解，应用于设计在压缩应变下工作的压电发电机。该器件由嵌入旋涂玻璃中的几平方毫米大小的 NW 阵列组成，具有肖特基接触以进行整流和收集压电产生的载流子。该发电机的最大功率密度约为 12.7 mW cm(-3)。这个值为基于 GaN NWs 且更一般地为基于氮化物 NWs 的压电发电机设定了新的技术水平，并为 GaN NWs 作为高效超紧凑能量收集器的应用提供了有前途的前景。
