1. A nitride-based semiconductor light-emitting device, comprising:
an n-type clad layer made of n-type Alx1Iny1Ga(1\u2212x1\u2212y1)N (where 0\u2266x1\u22661, 0\u2266y1\u22661, and 0\u2266x1+y1\u22661);
a multiple quantum well-structured active layer made of undoped InAGa1\u2212AN (where 0<A<1) formed on the n-type clad layer; and
a p-type clad layer formed on the active layer, including at least a first layer made of p-type Iny2Ga1\u2212y2N (where 0\u2266y2<1) formed on the active layer and a second layer made of p-type Alx3Iny3Ga(1\u2212x3\u2212y3)N (where 0<x3\u22661, 0\u2266y3\u22661, and 0<x3+y3\u22661) formed on the first layer.
2. The nitride-based semiconductor light-emitting device according to claim 1, wherein the first layer has a higher doping concentration than the second layer.
3. The nitride-based semiconductor light-emitting device according to claim 1, wherein the first layer has a thickness of about 100 nm or less,
4. The nitride-based semiconductor light-emitting device according to claim 3, wherein the first layer has a thickness of about 10 nm to about 30 nm.
5. The nitride-based semiconductor light-emitting device according to claim 1, wherein the p-type clad layer further includes a third layer made of p-type Iny4Ga1\u2212y4N (where 0\u2266y4<1) formed on the second layer.
6. The nitride-based semiconductor light-emitting device according to claim 5, wherein the third layer consist of a low concentration p-type GaN semiconductor layer having a first doping concentration formed on the second layer, and a high concentration p-type GaN semiconductor layer having a concentration higher than the first doping concentration formed on the low concentration p-type GaN semiconductor layer.
7. The nitride-based semiconductor light-emitting device according to claim 5, wherein the second layer has a thickness of about 50 nm to about 200 nm.
8. The nitride-based semiconductor light-emitting device according to claim 7, wherein the p-type clad layer has a thickness of at least 160 nm.
9. The nitride-based semiconductor light-emitting device according to claim 1, wherein the first layer is a GaN semiconductor layer and the second layer is an AlGaN semiconductor layer.
10. The nitride-based semiconductor light-emitting device according to claim 1, wherein the n-type clad layer is a GaN semiconductor layer.
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 tracking device for goods that are susceptible to disappear or get stolen, such as objects of arts and vehicles, inconspicuously mounted, sensor activated, allowing for instantaneous theft identification, simultaneously locating the goods and transmitting the corresponding information to the appropriate owner,
characterized by
1. an electronically undetectable sensor being a linear motion-sensor set to a pre-set motion distance, beyond which an signal enables the power supply to a secured electronic controller with tracking capabilities, preferentially over GPS, and transmits at least the location of the disappeared goods to their owner, upon which the device goes into a standby sleeping mode until new re-activation, either due to further motion triggering, through the preset timer or through a remote command by the owner.
2. the electronic controller characterized by remote activation capabilities through the transmitterreceiver of the tracking device, secured by a PIN number.
3. the electronic un-detectability of the tracking device per claims 1 and 2, characterized by a normally disabled power supply, whereby scan-able electromagnetic emissions of the device are inexistent.
4. the motion-sensor per claims 1 to 3, characterized by inertia-activation.
5. the motion-sensor per claims 1 to 3, characterized by GPS-activation.
6. the electronic controller per claims 1 through 4 is characterized by all location functions and stored data transfers performed by the tracking device.
7. the electronic controller per claims 1 through 3 and 5, characterized by all location functions and stored data transfers performed by the tracking device.
8. the electronic controller per claims 1 through 3 and 5 characterized by a locator based on any common geographic capable data transmittal systems, such as but not limited to GSM, PPRS, HSCSD, EDGE, WIFI, VFR, UHF, APRS.