Abstract: The invention relates to a color-tunable illumination system (10), to a lamp and to a luminaire. The color-tunable illumination system comprises a light source (20) emitting light of a first predefined color (B), and comprises a luminescent material (30) for converting light of the first predefined color into light of a second predefined color (A). The color-tunable illumination system further comprises shielding means (40, 42) arranged for preventing at least part of the light emitted by the light source to impinge on the luminescent material. The light source, the luminescent material and/or the shielding means are changeable from a first situation to a second situation. In the first situation the color-tunable illumination system is arranged for shielding at least part of the luminescent material against impinging light of the first predefined color.

Abstract: The present invention provides a field-effect transistor and method for the fabrication of a field-effect transistor by deposition on a substrate (480), which method comprises a wet chemical deposition of materials that react to form a semi-conducting material. The materials deposited include cadmium, zinc, lead, tin, bismuth, antimony, indium, copper or mercury. The wet chemical deposition may be by chemical bath deposition or spray pyrolysis. A vacuum deposition process is not required.