KR102382918B1 - Method and apparatus for simultaneous acquisition of conductive atomic force microscopy and lateral force microscopy signals for characterizing piezoelectric potential of ZnO nanorod - Google Patents

Abstract

The present invention relates to a method and an apparatus for measuring the characteristics of piezoelectric potential of ZnO nanorods through simultaneous signal measurement using conductive atomic force microscopy (C-AFM) and lateral force microscopy (LFM). The method comprises: a first step of bending nanorods grown using probing of C-AFM by applying vertical force thereto; a second step of obtaining by LFM, an LFM signal, which is a lateral force signal generated by twisting of the probing of the C-AFM; a third step of obtaining, by the C-AFM, a C-AFM signal, which is a current signal generated by an electric potential of the nanorods, through the probing; and a fourth step in which an efficiency characteristic calculation unit provides conversion efficiency for the amount of current output from the nanorods in preparation for the force applied to the nanorods by using the LFM signal and the C-AFM signal. Therefore, the conversion efficiency for the amount of current output from the nanorods in preparation for the force applied to the nanorods can be derived through simultaneous signal collection using the C-AFM and the LFM.

Description

Method and apparatus for simultaneous acquisition of conductive atomic force microscopy and lateral force microscopy signals for characterizing piezoelectric potential of ZnO nanorod

The present invention relates to a method and apparatus for measuring piezoelectric potential properties of ZnO nanowires, and more particularly, conduction atomic force microscope and lateral force microscope, which enables comprehensive analysis of the correlation between the force applied to the nanowire and the resulting output current. To a method and apparatus for measuring piezoelectric potential characteristics of ZnO nanowires through simultaneous signal measurement.

Atomic force microscopy (AFM) has played a key role in investigating the piezoelectric potential of nanowires or nanorods. An AFM probe can be used to deflect individual piezoelectric nanowires and measure the output current.

1, the performance evaluation method for the piezoelectric nanowire using an atomic force microscope (C-AFM: Conductive Atomic Force Microscopy) according to the prior art is divided into the AFM probe of a conductive atomic force microscope (C-AFM). The output current according to the piezoelectric potential generated by bending the nanorod was directly measured.

However, since the method of measuring the piezoelectric potential according to the prior art is only possible to measure the output current generated when the nanowire is bent, there is a problem in that the relationship between the force applied when bending the nanowire and the piezoelectric potential cannot be explained. there was.

The present invention has been devised to solve the above-mentioned problem, and the force applied to the nanowire through simultaneous signal collection of Conductive Atomic Force Microscopy (C-AFM) and Lateral Force Microscopy (LFM) It makes it possible to derive the conversion efficiency for the amount of current output from the nanowires and nanowires.

That is, the present invention intends to provide a comprehensive analysis on the correlation between the twist degree of a scanning probe of a conductive atomic force microscope (C-AFM) and the output current of the nanowire.

The method for measuring the piezoelectric potential characteristics of ZnO nanowires through simultaneous signal measurement of a conduction atomic force microscope and a lateral force microscope according to an embodiment of the present invention for solving the above-mentioned problems is a conductive atomic force microscope (C-AFM: Conductive Atomic Force Microscopy) A first step of bending by applying a force perpendicularly to the grown nanowire using a probe; a second step of obtaining an LFM signal, which is a lateral force signal generated by the twisting of the probe of the conduction atomic force microscope (C-AFM), using a lateral force microscope (LFM); a third step of obtaining, by the conduction atomic force microscope (C-AFM), a C-AFM signal that is a current signal generated by the electric potential of the nanowire through the probe; and a fourth step of using the LFM signal and the C-AFM signal by an efficiency characteristic calculator to provide conversion efficiency for the amount of current output from the nanowire in preparation for a force applied to the nanowire.

According to another embodiment of the present invention, in the second step, the lateral force microscope (LFM) obtains an LFM signal, which is a signal generated by twisting of the probe through a position-sensitive photodetector (PSPD). can

According to another embodiment of the present invention, in the fourth step, the efficiency characteristic calculating unit configures a dispersion degree using the LFM signal and the C-AFM signal as the X-axis and the Y-axis, respectively, and is applied to the nanowire. It is possible to provide conversion efficiency for the amount of current output from the nanowire against the force.

An apparatus for measuring the piezoelectric potential characteristics of a ZnO nanowire through simultaneous signal measurement of a conduction atomic force microscope and a lateral force microscope according to an embodiment of the present invention includes a probe that bends by applying a force perpendicular to the grown nanorod , Conductive Atomic Force Microscopy (C-AFM) for obtaining a C-AFM signal, which is a current signal generated by the electric potential of the nanowire, through the probe; Lateral Force Microscopy (LFM) for obtaining an LFM signal, which is a lateral force signal generated by torsion of the probe of the conduction atomic force microscope (C-AFM); and an efficiency characteristic calculator that provides conversion efficiency for the amount of current output from the nanowire in preparation for a force applied to the nanowire using the LFM signal and the C-AFM signal.

According to another embodiment of the present invention, the lateral force microscope (LFM) may be configured to include a position-sensitive photodetector (PSPD) that obtains an LFM signal, which is a signal generated by twisting of the probe. there is.

According to another embodiment of the present invention, the efficiency characteristic calculating unit configures a dispersion degree using the LFM signal and the C-AFM signal as an X-axis and a Y-axis, respectively, and prepares the above-mentioned efficiency characteristics in preparation for the force applied to the nanowire. It is possible to provide conversion efficiency with respect to the amount of current output from the nanowire.

According to the present invention, the force applied to the nanowire and the amount of current output from the nanowire through the simultaneous signal collection of Conductive Atomic Force Microscopy (C-AFM) and Lateral Force Microscopy (LFM) It is possible to provide the derivation of the conversion efficiency for .

More specifically, according to the present invention, it is possible to provide a comprehensive analysis on the correlation between the twist degree of a scanning probe of a conductive atomic force microscope (C-AFM) and the output current of the nanowire.

1 is a view for explaining a performance evaluation method for a piezoelectric nanowire using a conductive atomic force microscope (C-AFM: Conductive Atomic Force Microscopy) according to the prior art.
FIG. 2 is a view for explaining an apparatus for measuring piezoelectric potential characteristics of ZnO nanowires through simultaneous signal measurement by a conduction atomic force microscope and a lateral force microscope according to an embodiment of the present invention.
3 is a configuration diagram of a system for measuring piezoelectric potential characteristics of ZnO nanowires through simultaneous signal measurement by a conduction atomic force microscope and a lateral force microscope according to an embodiment of the present invention.
4 is a view for explaining a method for measuring the piezoelectric potential characteristics of a ZnO nanowire through simultaneous signal measurement by a conduction atomic force microscope and a lateral force microscope according to an embodiment of the present invention.
5 is a diagram illustrating a scanning electron microscope (SEM) measurement result of a nanowire according to an embodiment of the present invention.
6 is a view showing a scanning electron microscope (SEM) measurement image of ZnO nanowires for each sample according to an embodiment of the present invention.
7 and 8 are diagrams for explaining a method and results of measuring the piezoelectric potential characteristics of ZnO nanowires through simultaneous signal measurement by a conduction atomic force microscope and a lateral force microscope according to an embodiment of the present invention.
9 is a view for explaining the conversion efficiency of ZnO nanowires through the simultaneous signal measurement of a conductive atomic force microscope and a lateral force microscope according to an embodiment of the present invention.
10 and 11 are diagrams for explaining an interaction process between a conductive atomic force microscope (C-AFM) probe and a ZnO nanowire according to an embodiment of the present invention.
12 is a view for explaining a change in a conduction atomic force microscope (C-AFM) and a lateral force microscope (LFM) signal due to a change in the aspect ratio of a ZnO nanowire according to an embodiment of the present invention.

Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, in describing the embodiment, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, a detailed description thereof will be omitted. In addition, the size of each component in the drawings may be exaggerated for explanation, and does not mean the size actually applied.

2 is a view for explaining an apparatus for measuring the piezoelectric potential characteristics of a ZnO nanowire through simultaneous signal measurement of a conduction atomic force microscope and a lateral force microscope according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention It is a diagram for explaining a method of measuring the piezoelectric potential characteristics of ZnO nanowires through simultaneous signal measurement by a conduction atomic force microscope and a lateral force microscope.

According to the present invention, a vertically grown ZnO nanowire is bent to a sub-micron scale using a conductive atomic force microscope (C-AFM) probe. ZnO exhibits semiconductor and piezoelectric properties through the flow of charge carriers.

In the present invention, in order to explain the basic mechanism of generating a piezoelectric potential in ZnO nanowires and sensing a current signal through a conduction atomic force microscope (C-AFM) probe, a topography signal and a conduction atomic force microscope (C-AFM) : We will explain the correlation between the Conductive-Atomic Force Microscopy) signals.

2 and 3, the apparatus for measuring the piezoelectric potential characteristics of ZnO nanowires through simultaneous signal measurement of a conductive atomic force microscope and a lateral force microscope according to the present invention is a conductive atomic force microscope (C-AFM) (Conductive Atomic Force Microscopy) ( 110), a Lateral Force Microscopy (LFM) 120 and an efficiency characteristic calculating unit 130 may be included.

The conduction atomic force microscope (C-AFM: 110)) includes a probe that bends by applying a force perpendicular to the grown nanorod, a current signal generated by the electric potential of the nanowire through the probe. Obtain a C-AFM signal.

The lateral force microscope (LFM: 120) obtains an LFM signal, which is a lateral force signal generated by twisting of the probe of the conduction atomic force microscope (C-AFM). In this case, the lateral force microscope (LFM: 120) may be configured to include a position-sensitive photodetector (PSPD) that obtains an LFM signal, which is a signal generated by twisting of the probe.

In addition, the efficiency characteristic calculator 130 provides conversion efficiency for the amount of current output from the nanowire in preparation for the force applied to the nanowire using the LFM signal and the AFM signal. At this time, the efficiency characteristic calculating unit 120 configures a dispersion degree using the LFM signal and the AFM signal as the X-axis and the Y-axis, respectively, and the amount of current output from the nanowire in preparation for the force applied to the nanowire can provide conversion efficiency for

As shown in FIG. 3, when the probe 111 of the conduction atomic force microscope (C-AFM) touches the compressed surface of the n-type ZnO nanowire, the conduction atomic force microscope (C-AFM) detects a current signal. do. According to the present invention, the piezoelectric effect of n-type ZnO nanowires is clarified through comparative analysis of the topography signal and the conduction atomic force microscope (C-AFM) signal, and the effect of the ZnO nanowire growth method on piezoelectric power generation can understand the impact.

Conductive atomic force microscopy (C-AFM) is used to investigate the piezoelectric properties of one-dimensional nanomaterials with wurtzite structures such as CdS, CdSe, ZnS, InN, and GaN. Various types of sensors and energy harvesters based on piezoelectric nanomaterials are being intensively developed with various structures. Since these nanomaterials are easily affected by external forces, it is an important task to understand the physical properties of nanomaterials. Considering the size of these nanomaterials, lateral force microscopy (LFM) is an effective tool to investigate the elastic modulus of ZnO, Au, Si, and nanowires. In order to perform an accurate physical test on a single nanowire, conduction atomic force microscopy (C-AFM) scan was performed using a pre-programmed manipulation method to bend the nanowire, but a general conduction atomic force microscope (C-AFM) scan was performed. In the contact mode of , grown nanowires can be bent vertically.

A lateral force microscope (LFM) operates to measure the degree of torsion of a conductive atomic force microscope (C-AFM) cantilever through a position-sensitive photodetector (PSPD). On the other hand, due to the physical properties of the nanowire, the lateral force applied to the probe of a conductive atomic force microscope (C-AFM) can be regarded as the lateral force of the nanowire from the AFM probe. Therefore, according to the present invention, the ratio of the output current and the applied lateral force can be derived by simultaneously monitoring the conduction atomic force microscope (C-AFM) signal and the lateral force microscope (LFM) signal obtained by imaging the stand-alone piezoelectric nanowire.

Referring to Figure 4, the present invention operates a conduction atomic force microscope (C-AFM) and a lateral force microscope (LFM) at the same time to obtain a conduction atomic force microscope (C-AFM) current signal for a lateral force applied to a ZnO nanowire. By observing the change, the degree of torsion of the probe can be monitored by integrating a conductive atomic force microscope (C-AFM) instrument into the scanning electron microscope chamber while the AFM (including C-AFM) is operating. Although this method requires a sophisticated experimental arrangement, the simultaneous signal acquisition from the conduction atomic force microscope (C-AFM) and the lateral force microscope (LFM) can be easily performed even during the operation of the conduction atomic force microscope (C-AFM). can

Therefore, the method for characterizing the piezoelectric potential of ZnO nanowires through simultaneous signal measurement of conduction atomic force microscope and lateral force microscope according to the present invention can be used to study the size of ZnO nanowires that convert force into electric current through the piezoelectric effect. A change in the lateral force that occurs when a set of ZnO nanowire samples of a certain size is bent by a constant conduction atomic force microscope (C-AFM) probe at a certain normal force indicates a change in the applied force. Therefore, in the present invention, five ZnO nanowire samples with distinct aspect ratios were used to observe the ratio of output current to applied force.

On the other hand, in the conduction atomic force microscope (C-AFM)-based experiment on the piezoelectric effect of ZnO nanowires, the choice of the tip can have a significant effect on the results. This is because the proper normal force in the contact mode is determined by the spring constant of the probe. In addition, the properties of ZnO nanowires with respect to the efficiency of converting lateral force into electric current can be affected by the spring constant of the probe. Therefore, two probes with different spring constants were used for the ratio of output current to lateral force.

From now on, the ZnO nanometer by the conduction atomic force microscope (C-AFM) probe through the pixel-by-pixel comparison between the current signal versus the lateral force dispersion and the conduction atomic force microscope (C-AFM) and lateral force microscope (LFM) images according to the present invention. A method of generating a piezoelectric potential of a line will be described.

According to the present invention, it is possible to simultaneously acquire a conduction atomic force microscope (C-AFM) signal and a lateral force microscope (LFM) signal while the conduction atomic force microscope (C-AFM) probe scans the ZnO nanowire.

More specifically, when describing the method for measuring the piezoelectric potential characteristics of ZnO nanowires through simultaneous signal measurement of a conductive atomic force microscope and a lateral force microscope according to the present invention, first, a conductive atomic force microscope (C-AFM) probe By applying a force perpendicular to the grown nanorod using

In addition, a lateral force microscope (LFM: Lateral Force Microscopy) obtains an LFM signal, which is a lateral force signal generated by the torsion of the probe of the conduction atomic force microscope (C-AFM), and the conduction atomic force microscope (C-AFM) A C-AFM signal, which is a current signal generated by the electric potential of the nanowire, is obtained through the probe.

In this case, the lateral force microscope (LFM) may obtain an LFM signal, which is a signal generated by twisting of the probe, through a position-sensitive photodetector (PSPD).

Accordingly, the efficiency characteristic calculator may provide conversion efficiency with respect to the amount of current output from the nanowire in relation to the force applied to the nanowire by using the LFM signal and the C-AFM signal. In this case, the efficiency characteristic calculator configures a dispersion degree using the LFM signal and the C-AFM signal as the X-axis and the Y-axis, respectively, and converts the amount of current output from the nanowire in preparation for the force applied to the nanowire efficiency can be provided.

Referring to FIG. 2 , a conduction atomic force microscope (C-AFM) current signal is acquired through a current amplifier while a lateral force microscope (LFM) signal is transmitted through a position-sensitive photodetector (PSPD). Thus, conduction atomic force microscopy (C-AFM) signals and lateral force microscopy (LFM) signals operate in different ways, so that no interference occurs between the signals.

At this time, measurements of all conducted atomic force microscopy (C-AFM) signals and lateral force microscopy (LFM) signals were performed over a 10 μm×5 μm area using 512×128 data points. Every single element of the conducted atomic force microscopy (C-AFM) and lateral force microscopy (LFM) data can be expressed as C-AFM (i, j) and LFM (i, j) using matrix element notation.

Referring to FIG. 4 , a scatter plot was used to visually represent the correlation between the two data sets. Conducted atomic force microscopy (C-AFM) signals of n-type ZnO nanowires have negative values, and lateral force microscopy (LFM) signals during tracking and regression scans are positive and negative, respectively. Therefore, in order to reduce complexity, | C-AFM (i, j) | and | LFM (i, j) | was used.

5 is a view showing scanning electron microscopy (SEM) measurement results of nanowires according to an embodiment of the present invention, and FIG. 6 is a scanning electron microscope (SEM) of ZnO nanowires for each sample according to an embodiment of the present invention. It is a diagram showing a measurement image.

More specifically, FIG. 5A is a top view of a ZnO nanowire, and FIG. 5B is a side view of a ZnO nanowire.

5(c) and (d) show the measured length and diameter of vertically grown ZnO nanowires using scanning electron microscope (SEM) images. As the growth time increases, the aspect ratio of the ZnO nanowires is can be seen to increase. In addition, the name and growth conditions of each sample will be described later.

7 and 8 are views for explaining a method and results of measuring the piezoelectric potential characteristics of ZnO nanowires through simultaneous signal measurement by a conduction atomic force microscope and a lateral force microscope according to an embodiment of the present invention.

According to the present invention, conducted atomic force microscopy (C-AFM) and lateral force microscopy (LFM) measurements were performed on five samples using two different conducted atomic force microscopy (C-AFM) probes, as shown in FIG. As shown, the results during the tracking scan were presented using the current versus lateral force variance.

Probes A and B shown in FIG. 7 can be made of Si and then coated with electrically conductive materials such as Cr, Pt, and Ir with a thickness of less than 30 nm. The actual amount of current measured depends on the condition of the metal layer of the Conducted Atomic Force Microscopy (C-AFM) probe and the degree of wear. Therefore, the current value was normalized and an arbitrary unit was used as the current value.

Referring to FIG. 8 , it is possible to clearly observe the gradual change of the dot pattern in the distribution diagram as the aspect ratio increases regardless of the probe type. For example, in S6, where the aspect ratio of ZnO nanowires is relatively small, most data points are near the x-axis. This indicates that a fairly large lateral force was applied externally, but a small amount of current was generated. A gradual transition of the dot pattern is evident as the aspect ratio increases. In particular, in the distribution diagram of S30, data points with a lateral force of 7V or more are insufficient. This indicates that although S30 is accompanied by a relatively small lateral force, the resulting output current induced by the piezoelectric potential is noticeably enhanced. This trend can also be observed in the distribution plot generated by Probe A. This variation was quantitatively analyzed using a linear regression method, and a linear model is plotted on each distribution plot. The linear model derived accordingly is expressed as in Equation 1 below.

[Equation 1]

On the other hand, it is necessary to analyze the effect of the spring constant of the probe on the point pattern. Comparing the number of data points for which the lateral force exceeds 7 V (indicated by the dashed box) in the distribution plot of S18, the data point density decreases as the spring constant of the probe increases, resulting in 1496 for probe A and 184 for probe B. This indicates that the torsion degree decreases as the probe with a larger spring constant bends the ZnO nanowire and trims it. Also, it is clearly observed that data points greater than 7 V lateral force in probe B are not concentrated near the x-axis compared to probe A. Although large distortion sometimes occurs in probe B, it can be seen that the piezoelectric potential of the ZnO nanowire is effectively induced by the conduction atomic force microscope (C-AFM) probe. These characteristics appearing in the distribution plot can also be observed in the distribution plot set generated during the regression scan, as shown in Fig.

As described above, in the conduction atomic force microscopy (C-AFM) and lateral force microscopy (LFM) measurements of ZnO nanowires, the external force consists of a vertical force and a lateral force. All measurements were made by applying a constant force to the set point in the contact mode. The sum of the estimates according to the change in efficiency can be expressed as Equation 2 below.

[Equation 2]

In this case, α is a magnification factor considering the electrical conductivity and the set point level of the conductive atomic force microscope (C-AFM) probe. If one specific conduction atomic force microscopy (C-AFM) probe is used consistently on five samples (S6 to S30) at constant set points, the effect of α on the conversion efficiency is almost negligible. Also, no wear of the probe is observed while measuring 5 samples using a single probe. Therefore, transformation efficiencies were calculated for 5 samples for each probe in both tracking and regression scans.

It can be seen that the conversion efficiency calculated from the trace and regression data sets as in Fig. 9(a) increases as the aspect ratio increases. That is, this conversion efficiency value represents the ratio of the total current to the total lateral force. Therefore, the conversion efficiency is increased because the pattern of data points is concentrated near the y-axis. The pattern of data points can be effectively described by the slope of the linear model (p ₁ ) of Equation (1).

Fig. 9(b) shows the calculated p ₁ for 5 samples and 2 different probes. Overall, the value of p ₁ increases with increasing aspect ratio. The result of FIG. 9(b) effectively shows a tendency to generate a higher level of piezoelectric potential in the ZnO nanowire with a smaller external force as the aspect ratio of the ZnO nanowire increases. Accordingly, it can be seen that the results of the linear regression analysis and the conversion efficiency of Equation (2) are consistent with each other. As such, according to the present invention, it is possible to derive the conversion efficiency of the output current with respect to the applied force.

Hereinafter, an additional description will be given of the interaction process between the conductive atomic force microscope (C-AFM) probe and the ZnO nanowire according to the present invention.

Conducted atomic force microscopy (C-AFM) and lateral force microscopy (LFM) images containing 512 × 128 data points taken from the S6 sample by probes A and B are shown in Fig. 10(a) and (b).

Since the currents were normalized, the color bars of each conduction atomic force microscope (C-AFM) image were generated based on the minimum and maximum current values of the conduction atomic force microscope (C-AFM) images. Each conduction atomic force microscopy (C-AFM) and lateral force microscopy (LFM) image is indicated by rectangles '1' to '2', and enlarged images of the marked areas are indicated on the right.

According to FIG. 10, it can be confirmed that there is a strong correlation between conduction atomic force microscopy (C-AFM) and lateral force microscopy (LFM) through electromechanical bonding in ZnO nanowires. The degree of correlation is strongly affected by the probe type. Directly comparing the lateral force microscope (LFM) images of FIGS. 10 (a) and (b), it can be seen that the degree of torsion of the probe is alleviated when a probe having a large spring constant is used for imaging. In the lower part of (a) and (b) of Figure 10, the distribution of current versus lateral force for each pair of local conduction atomic force microscopy (C-AFM) and lateral force microscopy (LFM) images is shown below, and the local image This distribution map for is somewhat similar to the distribution map for the entire image of FIG. 7 .

Also, the proximity of the data point to the x-axis is determined by the probe's spring constant. If the local conduction atomic force microscope (C-AFM) and lateral force microscope (LFM) images are compared and described, for example, the lateral force microscope (LFM) image shown in (a)-1 of FIG. 10 when using the probe A Some of the active regions of , do not coincide with those of the conduction atomic force microscopy (C-AFM) image. This is because, when probe A having a spring constant of 0.2 N/m is used, there is a possibility that the ZnO nanowire is not deflected and the probe is twisted. Therefore, a large number of data points are concentrated near the x-axis. Conversely, even a small degree of torsion of probe B with 42 N/m spring constant can deflect the ZnO nanowires generating the current signal, so a large number of data points are slightly off the x-axis.

7 shows the change in the distribution of current with respect to the lateral force according to the aspect ratio of the ZnO nanowire. This gradual distribution change by probe B is clearly explained through pixel-by-pixel comparison between conducted atomic force microscopy (C-AFM) and lateral force microscopy (LFM) images, as shown in FIG. 12 . All conducted atomic force microscopy (C-AFM) and lateral force microscopy (LFM) images were generated based on the color bars indicated at the top of FIG. 12 . Referring to FIG. 12 , changes in conduction atomic force microscopy (C-AFM) and lateral force microscopy (LFM) signals can be observed due to changes in the aspect ratio of the ZnO nanowires. It can be seen from the enlarged image and the corresponding distribution diagram that as the aspect ratio increases, the current increases while the lateral force decreases.

As described above, the method and apparatus for measuring the piezoelectric potential characteristics of ZnO nanowires through simultaneous signal measurement of a conductive atomic force microscope and a lateral force microscope according to the present invention is a comprehensive method and apparatus for generating a piezoelectric potential in ZnO nano units using a probe is providing

In the present invention, a change in the ratio of the output current to the applied force according to the aspect ratio of the ZnO nanowire is observed by simultaneously acquiring the conduction atomic force microscope (C-AFM) and lateral force microscope (LFM) signals, and in particular, the spring constant is 0.2 N/ m and 42.0 N/m were used to investigate the effect of the spring constant on this analysis, and the lateral force to output current conversion efficiency was calculated and showed that the efficiency improved with increasing aspect ratio. In addition, a distribution map of current versus lateral force was created, and a change in the dot pattern according to the aspect ratio change was quantitatively analyzed using a linear model based on a linear regression method. In addition, the resulting linear model showed that the slope increased as the aspect ratio of the ZnO nanowires increased. This indicates that the data points of the distribution plot shift from the lateral force axis (x-axis) to the current axis (y-axis) as the aspect ratio increases.

As such, the method and apparatus for measuring piezoelectric potential properties of nanowires according to the present invention can be applied to all piezoelectric nanomaterials grown vertically, and the effect of growth conditions on the conversion efficiency of applied mechanical force into output current can be easily investigated. can In addition, the change in the scattering pattern due to the distinct aspect ratio can be clearly confirmed through pixel-by-pixel comparison between conducted atomic force microscopy (C-AFM) and lateral force microscopy (LFM) images.

In the detailed description of the present invention as described above, specific embodiments have been described. However, various modifications are possible without departing from the scope of the present invention. The technical spirit of the present invention should not be limited to the above-described embodiments of the present invention, and should be defined by the claims as well as the claims and equivalents.

Claims (5)

A first step of bending by applying a vertical force to the grown nanowire (nanorod) using a probe of a conductive atomic force microscope (C-AFM: Conductive Atomic Force Microscopy);
Lateral Force Microscopy (LFM) uses a position-sensitive photodetector (PSPD) to obtain an LFM signal, which is a lateral force signal generated by the twisting of the probe of the conduction atomic force microscope (C-AFM). Step 2;
a third step of obtaining, by the conduction atomic force microscope (C-AFM), a C-AFM signal that is a current signal generated by the electric potential of the nanowire through the probe; and
Efficiency characteristic calculation unit constitutes a dispersion degree of the LFM signal and the C-AFM signal as the X-axis and the Y-axis, respectively, and the conversion efficiency for the amount of current output from the nanowire in preparation for the force applied to the nanowire a fourth step of providing;
A method for measuring the piezoelectric potential characteristics of ZnO nanowires through simultaneous signal measurement of a conductive atomic force microscope and a lateral force microscope.
delete delete Conducted atomic force microscope (C-AFM) to obtain a C-AFM signal, which is a current signal generated by the electric potential of the nanowire, through the probe, including a probe that is bent by applying a force perpendicular to the grown nanorod : Conductive Atomic Force Microscopy);
Lateral Force Microscopy (LFM) including a position-sensitive photodetector (PSPD) for obtaining an LFM signal, which is a lateral force signal generated by twisting of the probe of the conduction atomic force microscope (C-AFM); and
Efficiency characteristics that provide conversion efficiency for the amount of current output from the nanowire in preparation for the force applied to the nanowire by configuring a dispersion degree using the LFM signal and the C-AFM signal as the X-axis and the Y-axis, respectively output unit;
A device for measuring the piezoelectric potential properties of ZnO nanowires through simultaneous signal measurement of a conduction atomic force microscope and a lateral force microscope.
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