1. Charge Coupled Device (CCD)
Ingle and Crouch, Spectrochemical Analysis

2. CCD Architecture Image Area SiO2 backing Pixel Array serial register
amplifier
and Bryce Marquis (Haynes Lab)

3. Bryce Marquis (Haynes Lab)
CCD Architecture
“Channel Stops” form horizontal pixel boundaries
Top View
3 electrodes
form vertical
pixel boundaries
One pixel
Electrode
Insulating oxide
n-type silicon
p-type silicon
Cross section
Bryce Marquis (Haynes Lab)

4. Charge Generation/Collection-V +V -V -V +V -V
N-type
P-type
Incident photons excite electron-hole pairs,
electrons gather in potential wells in each pixel

5. CCD Rain Bucket Analogy
1. Generation
2. Collection
3. Transfer
4. Measurement
Shinya Inoue and Kenneth Spring, Video Microscopy, Plenum Press, New York, 1997.

6. Charge Generation/Collection-V +V -V -V +V -V
N-type silica is doped with pentavalent species = excess electrons
P-type is doped with trivalent species = excess holes
N-type
Potential Well
P-type
One Pixel

7. Charge Transfer Every third electrode is 2 coupled, charge packets
are walked towards
Serial registry 2
+5V 0V
-5V 1
+5V 0V
-5V 3
to serial registry 1 2 3
Time-slice shown in diagram

8. +5V 0V
-5V 2
+5V 0V
-5V 1
+5V 0V
-5V 3 1 2 3

9. +5V 0V
-5V 2
+5V 0V
-5V 1
+5V 0V
-5V 3 1 2 3

10. +5V 0V
-5V 2
+5V 0V
-5V 1
+5V 0V
-5V 3 1 2 3

11. +5V 0V
-5V 2
+5V 0V
-5V 1
+5V 0V
-5V 3 1 2 3

12. +5V 0V
-5V 2
+5V 0V
-5V 1
+5V 0V
-5V 3 1 2 3

13. +5V 0V
-5V 2
+5V 0V
-5V 1
+5V 0V
-5V 3 1 2 3

14. Charge Transportation
amplifier
Pixels at end of the array dump charge into serial register
Serial register walks charge packets to amplifier, where it is measured.

15. Quantum Efficiency

16. Noise Sources in CCD Shot Noise Dark Signal Noise Readout Noise
Statistical variation of signal over time
Increases with the square of the intensity
Dark Signal Noise
Caused by thermal liberation of electrons
Strongly coupled to temperature
Readout Noise
Summation of noise associated with amplification of signal, and conversion from analogue to digital
Increases with the processing speed

17. Other Issues: Bad Pixels
Increasing hot pixels
Hot Pixels
Increased charge accumulation due to variations in chip surface.
Dead Pixels
Defective pixels that do not respond.

18. Other Issues: Blooming

19. Other Issues: Cosmic Rays
Noise From Outer Space!!!
* indicates cosmic rays

20. Other Issues: Etaloning

21. Other Features: Binning
On Chip Pixel Binning
Increases S/N
Shot noise decrease
Increased speed
Less storage space needed
Decreases resolution

22. Are you getting the concept?
List the advantages and disadvantages of using each of the discussed detectors to achieve single molecule detection.