All pnCCD (S)TEM camera models provide the tremendous advantage of direct electron measurement. As no scintillator is required, the primary TEM electrons are absorbed directly in the sensor bulk and the created secondary charges are read out with highest precision. Hence ,PNDetectors’ pnCCD (S)TEM camera provides unique single electron detection sensitivity and simultaneously is capable to measure their energy with very high precision.

pnCCD System

pnCCD Properties

Fixed bottom camera

Retractable camera

PNOnline Software

Highlights

Working Principle

Electron Ptychography

Diffraction Pattern Analysis

Electric / Magnetic field mapping

Strain mapping

Single Electron Detection

Dynamic TEM Imaging

Low Voltage / Low Dose Imaging

The following camera specifications are valid for all pnCCD (S)TEM camera models

Physical pixel size 48 µm × 48 µm × 450 µm
Number of physical pixels 264 × 264 (69,696) full frame area, plus frame store area
Active area 12.7 mm × 12.7 mm (161 mm2) full frame area
Frame rate in full frame mode up to 1,000 fps (264 × 264 pixel)
Binning modes (examples)   

2-fold binning: 264 x 132 macropixel (2000 fps)

4-fold binning: 264 x 66 macropixel (4000 fps)

Windowing modes (examples)

132 x 264 pixel (2000 fps)

24 × 264 pixels (10000 fps)

High speed Option

Up to 2000 fps in full frame mode (264 x 264 pixel)

4000 fps using 2-fold binning (264 x 132 macropixel)

7500 fps using 4-fold binning (264 × 66 macropixel)

Image integration time down to 100 µs
Signal (per 80 keV primary electron)    22000 signal electrons
Readout noise (RMS) typically 30 signal electrons
Charge handling capacity up to 400000 signal electrons per pixel
Radiation hardness

>1 x 1018  TEM electrons (80 keV) per cm²

>4 x 1017 TEM electrons (200 keV) per cm²

Externally triggerable Yes (accepts up to 4 triggers)

PNOnline Software

The PNOnline software provides all the functionality necessary to control the PNDetector’s pnCCD (S)TEM camera system and conveniently acquire high quality data. Versatile live displays provide instantaneous feedback about the bright field disk or diffraction pattern on the detector and allow effective adjustment of the camera settings. Data can be recorded in STEM or TEM measurement mode and is saved in PNDetectors’ frms6 file format which guarantees full raw data access, and can easily be used with common data analysis frameworks, like the LiberTEM project. Various masks can be selected for flexible live synthetic imaging.

The pnCCD Principle

The pnCCDs are back illuminated, three-phase CCDs on a fully depleted silicon substrate. Their operation is based on the principle of sideward depletion and on transfer registers formed by pn-junctions. The outstanding characteristics include a homogeneous and thin photon entrance window leading to high quantum efficiency values between 100 eV and 20 keV and an excellent radiation hardness as well as high charge handling capacity.