Observation of p–n junction in transmission electron microscopy by out-of-focus technique

Merli, P. G.; Missiroli, G. F.; Pozzi, Giulio

doi:10.1002/pssa.2210160239

Cited by 11 publications

(6 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The GaAs sample was characterized by electron holography and Lorenz TEM techniques prior to DPC STEM imaging. By comparing with these existing methods 18 19 , the capabilities and benefits of the present imaging method are independently verified. The sample thickness is estimated to be about 290 nm from convergent beam electron diffraction analysis.…”

Section: Methodsmentioning

confidence: 90%

Imaging of built-in electric field at a p-n junction by scanning transmission electron microscopy

Shibata

Findlay

Sasaki

et al. 2015

Sci Rep

132

View full text Add to dashboard Cite

Precise measurement and characterization of electrostatic potential structures and the concomitant electric fields at nanodimensions are essential to understand and control the properties of modern materials and devices. However, directly observing and measuring such local electric field information is still a major challenge in microscopy. Here, differential phase contrast imaging in scanning transmission electron microscopy with segmented type detector is used to image a p-n junction in a GaAs compound semiconductor. Differential phase contrast imaging is able to both clearly visualize and quantify the projected, built-in electric field in the p-n junction. The technique is further shown capable of sensitively detecting the electric field variations due to dopant concentration steps within both p-type and n-type regions. Through live differential phase contrast imaging, this technique can potentially be used to image the electromagnetic field structure of new materials and devices even under working conditions.

show abstract

Section: Methodsmentioning

confidence: 90%

Imaging of built-in electric field at a p-n junction by scanning transmission electron microscopy

Shibata

Findlay

Sasaki

et al. 2015

Sci Rep

132

View full text Add to dashboard Cite

show abstract

“…Therefore, by carefully positioning an aperture over the distorted spot, an image sensitive to the electric field can be obtained. Shortly after, Merli et al reported the imaging of Si p–n junctions using the “Fresnel” or “out-of-focus” method. As suggested by its name, this method makes use of a defocused electron beam and can be used in both conventional and scanning modes. , However, defocused TEM imaging suffers from interpretability and spatial resolution issues.…”

mentioning

confidence: 99%

Quantitative Characterization of Nanometer-Scale Electric Fields via Momentum-Resolved STEM

et al. 2021

View full text Add to dashboard Cite

Most of today's electronic devices, like solar cells and batteries, are based on nanometer-scale built-in electric fields. Accordingly, characterization of fields at such small scales has become an important task in the optimization of these devices. In this study, with GaAs-based p−n junctions as the example, key characteristics such as doping concentrations, polarity, and the depletion width are derived quantitatively using four-dimensional scanning transmission electron microscopy (4DSTEM). The built-in electric fields are determined by the shift they introduce to the center-of-mass of electron diffraction patterns at subnanometer spatial resolution. The method is applied successfully to characterize two p−n junctions with different doping concentrations. This highlights the potential of this method to directly visualize intentional or unintentional nanoscale electric fields in real-life devices, e.g., batteries, transistors, and solar cells.

show abstract

“…It is assumed that the internal field profile of the junction is the same both i n the thick and thinned specimens, that is, thickness and surface effects are considered to be negligible. Assuming that the model is of the one-sided step junction type [14] the electric field E within the depletion layer region is given by 5.7 x 10-5 6.0 x 10-5 8.9 x 10-5 1.0 x 10-4 6.8 X where W is the depletion layer width and X the distance of the point considered from the maximum of the field. The field is zero outside the depletion layer region.…”

Section: Deflection By the Internal Fieldmentioning

confidence: 99%

Transmission electron microscopy observations of p–n junctions

Merli

Missiroli²,

Pozzi³

1975

Phys. Stat. Sol. (a)

Self Cite

View full text Add to dashboard Cite

Defocusing, low‐angle selected area diffraction and Foucault technique have been applied, working with a Siemens Elmiskop 101, to the observation of the microelectric field associated to a reverse‐biased p–n junction. It is shown that, in order to obtain information about the main features of the total electric field, it is necessary to combine all three methods. The first one yields the location of the depletion layer region and allows the drawing of a map of the leakage field. On the basis of these data it becomes possible to interpret the low‐angle electron diffraction pattern and, consequently, to locate correctly the contrast aperture in order to obtain in focus, with the Foucault method, an amplitude contrast due to the microelectric field. The region where the external leakage field or the depletion layer is present is thus detectable in focus.

show abstract

Observation of p–n junction in transmission electron microscopy by out-of-focus technique

Cited by 11 publications

References 2 publications

Imaging of built-in electric field at a p-n junction by scanning transmission electron microscopy

Imaging of built-in electric field at a p-n junction by scanning transmission electron microscopy

Quantitative Characterization of Nanometer-Scale Electric Fields via Momentum-Resolved STEM

Transmission electron microscopy observations of p–n junctions

Contact Info

Product

Resources

About