Electroluminescent devices formed using semiconductor nanocrystals as an electron transport media and method of making such electroluminescent devices

An electroluminescent device capable of emitting visible light of a particular wavelength upon application of a voltage thereto, which comprises:

• a) hole processing means capable of injecting and transporting holes;
• b) an electron transport layer in contact with said hole processing means comprising one or more monolayers of semiconductor nanocrystals capable of emitting visible light of a particular wavelength and having an average cross-section no larger than about 20 nm.;
• and
• c) an electron injecting layer in contact with said electron transport layer for injecting electrons into said electron transport layer.

An electroluminescent device characterized by the capability of emitting visible light of varying wavelengths based on variations in voltage applied thereto and comprising:

• a) a hole injection layer;
• b) a hole transport layer in contact with said hole injecting layer for transporting therethrough said holes injected therein;
• c) an electron transport layer in contact with said hole transport layer comprising one or more layers of semiconductor nanocrystals comprising single crystal semiconductor material having a particle size of not more than about 10 nm.;
• and
• c) an electron injecting layer in contact with said electron transport layer for injecting electrons into said electron transport layer.

An electroluminescent device characterized by the capability of emitting visible light of varying wavelengths based on variations in voltage applied thereto and comprising:

• a) a hole injection layer, comprising a conductive layer capable of injecting holes into said device;
• b) a hole transport layer in contact with said hole injecting layer for transporting therethrough said holes injected therein;
• c) an electron transport layer in contact with said hole transport layer comprising one or more layers of semiconductor nanocrystals selected from the group consisting of group II-VI semiconductors and group III-V semiconductors, and comprising single crystal semiconductor material having a particle size of not more than about 10 nm.;
• and
• c) an electron injecting layer in contact with said electron transport layer and comprising a metal layer capable of injecting electrons into said electron transport layer comprising said semiconductor nanocrystals;
• wherein at least one of said layers is transparent to visible light.

A method of making an electroluminescent device comprising:

• a) forming hole processing means capable of injecting and transporting holes;
• b) forming electron transport means in contact with said hole processing means comprising one or more monolayers of semiconductor nanocrystals capable of emitting light and having an average cross-section no larger than about 20 nm.;
• and
• c) forming electron injecting means in contact with said electron transport means for injecting electrons into said electron transport means.

A flat-panel display for providing an image utilizing emitted light from a plurality of electroluminescent devices, said display comprising:

• a) a plurality of electroluminescent devices arranged in an array, each of said electroluminescent devices comprising:
• i) hole processing means capable of injecting and transporting holes;
• ii) an electron transport layer in contact with said hole processing means comprising one or more monolayers of semiconductor nanocrystals having an average cross-section no larger than about 20 nm.;
• and
• iii) an electron injecting layer in contact with said electron transport layer for injecting electrons into said electron transport layer;
• b) a first electronic control input unit capable of receiving one or more input signals and operably coupled to said array of electroluminescent devices;
• and
• c) a second electronic control input unit also capable of receiving one or more input signals and also operably coupled to said array of electroluminescent devices;
• whereby said first and second electronic control input units are arranged to provide voltages across preselected portions of said array of electroluminescent devices, in response to said input signals, to provide said image.

An electroluminescent device comprising:

• a) hole processing means capable of injecting and transporting holes;
• b) electron transport means in contact with said hole processing means comprising one or more monolayers of inorganic semiconductor nanocrystals;
• and
• c) electron injecting means in contact with said electron transport means for injecting electrons into said electron transport means.

A method of making an electroluminescent device comprising:

• a) forming hole processing means capable of injecting and transporting holes;
• b) forming electron transport means in contact with said hole processing means comprising one or more monolayers of inorganic semiconductor nanocrystals capable of emitting light;
• and
• c) forming electron injecting means in contact with said electron transport means for injecting electrons into said electron transport means.

A flat-panel display for providing an image utilizing emitted light from a plurality of electroluminescent devices, said display comprising:

• a) a plurality of electroluminescent devices arranged in an array, each of said electroluminescent devices comprising:
• i) hole processing means capable of injecting and transporting holes;
• ii) an electron transport layer in contact with said hole processing means comprising one or more monolayers of inorganic semiconductor nanocrystals;
• and
• iii) an electron injecting layer in contact with said electron transport layer for injecting electrons into said electron transport layer;
• b) a first electronic control input unit capable of receiving one or more input signals and operably coupled to said array of electroluminescent devices;
• and
• c) a second electronic control input unit also capable of receiving one or more input signals and also operably coupled to said array of electroluminescent devices;
• whereby said first and second electronic control input units are arranged to provide voltages across preselected portions of said array of electroluminescent devices, in response to said input signals, to provide said image.