Ch : LED Ging vin: V Ngc Chm

Ch :LED Diode pht quangCu kin in tGing vin: V Ngc Chm Nhm 4 7- TVT1:1. Nguyn Th Thu Hng2. Nguyn Th Hng Thy3. Trn Th Diu Linh4. L Th Linh

Ni dungS lc v LEDCu to v k hiuNguyn tc hot ng Phn loing dngTm hiu thm v LED

Mt s hnh nh v LED

1. LED (Light Emitting Diode)LED l linh kin bn dn quang c kh nng pht ra nh sng khi c hin tng ti hp P - N.Ty vo vt liu ch to m nh sng bc x ca LED l khc nhau: nh sng nhn thy (LED mu), hng ngoi (LED hng ngoi), t ngoi.nh sng do LED pht ra l nh sng khng kt hp, t pht v ng hng.52. Cu to v k hiu

LED c cu to t mt khi bn dn loi p ghp vi mt khi bn dn loi n mc ni tip vi mt in tr hn dng.

Vt liu ch to LEDVt liu ch to LED l cc nguyn t nhm III v V: GaAs, GaP, GaAsP, hoc lin kt 3 nguyn t nh GaAsP, v.v.. y l cc vt liu ti hp trc tip, c ngha l s ti hp xy ra gia cc in t st y di dn v cc l trng st nh di ha tr.

Vt liu v mu nh sng bc x

Cu trc ca LEDLED vm v LED phng c s dng trong phn ln cc thit b hin th vi li ch l rt c lng nh sng cc i t thit b => nh sng c pht ra theo tt c cc hng v s dng cc ng knh c sp xp theo trt t nht nh hi t nh sng.

Cu to n LED

3.Nguyn l hot ng

LED s pht quang khi c phn cc thun, ngha l bin i nng lng in thnh nng lng quang.Cng pht sng t l vi dng qua LED.Khi LED phn cc thun, cc ht dn a s khuch tn t qua tip xc P-N, in t bn N s khuch tn sang P v l trng bn P s khuch tn sang N.Trong qu trnh di chuyn chng s ti hp vi nhau v pht ra photon

c tuyn Vn - Ampe caLED

c tuyn Vn - Ampe ca it pht quang biu din mi quan h gia dng in quang vi in p t ln LED.in p phn cc thun UD: 1,6 3 V; in p phn cc ngc: 3 5 V; dng ID khong vi chc mA.

Cc tham s ca LEDVt liu:V nguyn tc tt c cc chuyn tip P N u c kh nng pht ra nh sng khi c phn cc thun nhng ch c mt s loi vt liu ti hp trc tip mi cho hiu sut ti hp cao.Mt s loi LED thng dng:

b)Nhit :Khong nhit lm vic ca LED: -600C n +800CLED rt nhy vi nhit :Nhit cng tng bc sng ca LED cng ngn (bc sng gim 0,02 0,09m/0C)Nhit tng cng bc x quang gim (1%/0C)c)Cng sut pht x: vi trm W n vi mW

4. Phn loi LEDLED mu:LED nLED iLED 7 thanh:Kiu Anot chung: ghp cc cc Anot vi nhau th cc u iu khin i vo cc catot (iu khin bng xung m)Kiu Catot chung: ngc li vi kiu Anot chungLED hng ngoi

5. ng dngTui th ca LED khong 100 ngn gi. u im ca LED: gn nh, bn, tit kim nng lng.

LED muLED pht ra nh sng nhn thy c dng lm b phn hin th trong cc thit b in, in t, n qung co, trang tr, n giao thng,

LED hng ngoiCc LED pht ra tia hng ngoi c s dng trong cc h thng thng tin quang hoc cc h thng iu khin hoc bo mt.

6. Tm hiu thm v LEDLED hng ngoi LED hng ngoi c hiu sut cao hn LED mu v tia hng ngoi khng b yu i khi vt qua cc lp bn dn ra ngoi

b) LED pht x mt v LED pht x cnh

LED pht x mt v LED pht x cnh ch yu c s dng trong cc h thng thng tin si quang.

Lch s ca LEDn LED c mt t nhng thp nin 60, hu ht chi dng hin th thi gian ca ng h bo thc hay dung lng pin ca my ghi hnh.Mt thi gian di, n LED khng c dng lm ngun sng bi v chng ch cho nh sng , xanh l cy v vng m khng cho nh sng trng.n nm 1993, cng ty ho cht Nichia ca Nht Bn cho ra i loi n LED xanh dng, l s kt hp gia nh sng v xanh l cy cho ra nh sng trng.

Bn c bit?Cng trnh nghin cu ca cc nh khoa hc i hc Exeter (M) tm hiu cu trc c bit ca cnh bm c bao bc bi lp vy siu nh, c kh nng tip nhn tia cc tm v pht sng tr li gip bm lin lc vi nhau.Loi bm chu Phi tn dng LED trong thin nhin. n LED hot ng theo c ch ging loi bmcc nh khoa hc pht trin cng ngh n chiu sng cao cp, h khng nhn ra rng loi bm chu Phi s dng phng php tng t trong hn 30 triu nm Chng c cnh en vi nhng sc t mu xanh sng hoc xanh ngc. Lp sc t hot ng nh nhng tinh th nh sng 2D v ta ra nh sng hunh quang.C ch ny ging LED.Cm n thy c v cc bn ch lng nghe!