1. A field ion mobility analytical system comprising:
a pair of electrode banks defining between them a flow path,
an ion separator and an ion detector, said separator and said detector for making trajectory-based ion species identification of ions flowing in said flow path between said banks, said electrodes being separated by an analytical gap,
each said bank comprising at least one separator electrode for forming said ion separator, at least one said bank having a plurality of electrodes, at least one of said plurality of electrodes comprising a detector electrode,
an electrical controller input for applying a time-varying voltage to said ion separator and generating a transverse time-varying electric field between said separator electrodes while the ions are flowing along the flow path for controlling the paths of said ions in said separator, said field causing selected ions of said flow of ions to contact said detector electrode based on ion mobility in the field and consequent ion trajectory,
said ions contacting said detector being identifiable based at least in part on said trajectory.
2. System of claim 1 further comprising an analytical package, said package forming said ion separator, said ion detector and said banks associated with said flow path.
3. System of claim 2 wherein said banks are spaced apart forming an analytical gap.
4. System of claim 3 wherein said gap is about 0.5 mm between facing electrodes on said banks.
5. System of claim 1 wherein said plurality of electrodes comprises a plurality of detector electrodes.
6. System of claim 1 further comprising at least one low noise amplifier, wherein said detection at said detector electrode is communicated to said controller via said amplifier.
7. System of claim 1 wherein said electrodes form an integrated ion filter-detector for simultaneous detection of distinct species of ions based on their trajectory according to their mobility in said asymmetric field, and wherein said field includes a RF field.
8. System of claim 1 further comprising a detector downstream from said banks for detecting ions that exit said separator.
9. System of claim 1 wherein said detector includes a plurality of segments, said segments separated along said flow path to spatially detect said ions according to their trajectories.
10. A high field ion mobility spectrometer for analysis of compounds in a sample, comprising:
a source of charged ions representative of compounds in a sample,
an ion flow path,
a plurality of electrodes forming banks along said flow path, said banks facing each other over said flow path down stream from said source, said charged ions flowing between said banks in said flow path, each said bank including at least one filter electrode,
a controller input for application of time-varying voltages to said filter electrodes for inducing a time-varying electric field between said filter electrodes while the ions are flowing along the flow path, said charged ions being subjected to said field between said banks, said field imparting a respective trajectory to a respective charged ion according to ion mobility characteristics of said respective charged ion, and
at least one of said banks defining at least one detector electrode, said detector electrode for receipt of charge deposits from species of said charged ions having common trajectories.
11. The spectrometer of claim 10 wherein said at least one of said banks having said at least one detector electrode comprises a multi-function bank of electrodes and faces the other said bank across said flow path.
12. The spectrometer of claim 11 wherein said multi-function bank comprises an array of filter electrodes, wherein one of said filter electrodes is also said detector electrode.
13. The spectrometer of claim 11 wherein said multi-function bank comprises an array of filter electrodes, wherein said filter electrodes are detector electrodes.
14. The spectrometer of claim 11 wherein said multi-function bank comprises an array of detector electrodes, wherein said array of detector electrodes is formed interspersed with said filter electrodes.
15. The spectrometer of claim 10 wherein said mobility characteristics are based on ion features including size, charge, and cross-section of said charged ions.
16. The spectrometer of claim 10 wherein said ions are carried in a carrier gas in said flow path.
17. The spectrometer of claim 10 wherein said ions are electrically propelled in said flow path.
18. The spectrometer of claim 11 wherein said multi-function bank comprises an array of detector electrodes, wherein said array includes said at least one detector electrode, said controller enabling simultaneous detection of ion species on a respective one of said detector electrodes based on differences in trajectory.
19. The spectrometer of claim 10 wherein said electrodes form an integrated ion filter-detector for simultaneous detection of distinct species of ions based on their trajectory according to their mobility in said time-varying field.
20. Method for identification of a chemical in a sample, comprising the steps of:
i) ionizing the sample,
ii) flowing the sample as a flow of ions along a flow path between a series of electrodes,
iii) providing a time-varying electric field between said electrodes while the ions are flowing along the flow path and generating mobility behavior of said ions,
iv) separating said ions according to species, said separation based on said behavior in said field as expressing mobility characteristics of said species, and
v) providing an ion separator and an ion detector, said separator and said detector including a plurality of electrodes in said series of electrodes, for making trajectory-based ion species identification.
21. Method of claim 20 further comprising the step of applying at least one high voltage to said ion separator and generating a transverse high electric field between said separator electrodes for controlling the paths of said ions in said separator, said field causing selected ions of said flow of ions to contact said detector electrode based on ion mobility in the high field and consequent ion trajectory, and said selected ions forming an ion species defined as having the same ion mobility and said selected ions contacting said detector electrode at said flow rate.
22. Method of claim 20 comprising identifying ion species based on a carrier flow rate and field conditions.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A photodetecting device having quantum dots, comprising:
a quantum dot structure including a first embedding layer, and quantum dots embedded by said first embedding layer; and
a quantum well structure formed at a location downstream of said quantum dot structure in a direction of flow of electrons which flow perpendicularly to said quantum dot structure during operation of the photodetecting device, said quantum well structure including second and third embedding layers, and a quantum well layer which is sandwiched between said second and third embedding layers, and whose band gap is smaller than those of said second and third embedding layers.
2. The photodetecting device according to claim 1, wherein said quantum dot structure and said quantum well structure are formed in an alternating manner a plurality of times in layers.
3. The photodetecting device according to claim 1, wherein aluminum gallium arsenide is used in forming said first, second, and third embedding layers.
4. The photodetecting device according to claim 1, wherein indium arsenide or indium gallium arsenide is used in forming said quantum dots.
5. The photodetecting device according to claim 1, wherein gallium arsenide is used in forming said quantum well layer.
6. A method of manufacturing a photodetecting device having quantum dots, the method comprising the steps of:
forming a quantum dot structure including a first embedding layer, and quantum dots embedded by the first embedding layer; and
forming a quantum well structure at a location downstream of the quantum dot structure in a direction of flow of electrons which flow perpendicularly to the quantum dot structure during operation of the photodetecting device, the quantum well structure including second and third embedding layers, and a quantum well layer which is sandwiched between the second and third embedding layers, and whose band gap is smaller than those of the second and third embedding layers.
7. The method according to claim 6, the quantum dot structure and the quantum well structure are formed in an alternating manner a plurality of times in layers.
8. The method according to claim 6, aluminum gallium arsenide is used in forming the first, second, and third embedding layers.
9. The method according to claim 6, indium arsenide or indium gallium arsenide is used in forming the quantum dots.
10. The method according to claim 6, gallium arsenide is used in forming the quantum well layer.