Photoelectric Transducer Device

• US 20120019222A1
• Filed: 06/01/2011
• Published: 01/26/2012
• Est. Priority Date: 06/04/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kimura, Hajime, Yamazaki, Shunpei, Ito, Yoshiaki, Ohmaru, Takuro
• Granted Patent: US 9,667,148 B2
• Time in Patent Office: Days
• US Class Current: 323/282
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 27/1233 with different thicknesses of the active layer in different devices
• CPC Class Codes: H01L 31/048 Encapsulation of modules
• CPC Class Codes: H02M 3/1588 comprising at least one synchronous rectifier element H02M3/1582, H02M3/1584 take precedence
• CPC Class Codes: H02S 40/32 comprising DC/AC inverter means associated with the PV module itself, e.g. AC modules
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y02E 10/548 Amorphous silicon PV cells

Abstract

An object is to obtain a rectifier having a small voltage drop and to reduce the fabrication cost of a converter circuit. A photoelectric transducer device including: a photoelectric transducer element; and a converter circuit stepping up or stepping down an output of the photoelectric transducer element and including a switching element and a rectifier, in which the switching element is a first oxide semiconductor transistor that is normally off and in which the rectifier is a second oxide semiconductor transistor that is diode-connected and normally on.

Claims

1. A photoelectric transducer device comprising:

a photoelectric transducer element; and

a converter circuit stepping up or stepping down an output of the photoelectric transducer element and including a switching element and a rectifier,

wherein the switching element is a first oxide semiconductor transistor that is normally off, and

wherein the rectifier is a second oxide semiconductor transistor that is diode-connected and normally on.

2. The photoelectric transducer device according to claim 1,

wherein the first oxide semiconductor transistor and the second oxide semiconductor transistor each comprise:

an island-shaped oxide semiconductor layer including a channel formation region;

a source electrode in contact with the island-shaped oxide semiconductor layer; and

a drain electrode in contact with the island-shaped oxide semiconductor layer, and

wherein a first region of the island-shaped oxide semiconductor layer having no overlap with the source electrode or the drain electrode is thinner than a second region of the island-shaped oxide semiconductor layer overlapping with the source electrode or the drain electrode.

3. The photoelectric transducer device according to claim 1,

wherein the first oxide semiconductor transistor and the second oxide semiconductor transistor each comprise:

an island-shaped oxide semiconductor layer including a channel formation region;

a source electrode over the island-shaped oxide semiconductor layer; and

a drain electrode over the island-shaped oxide semiconductor layer, and

wherein two oxide semiconductor layers having higher conductivity than the island-shaped oxide semiconductor layer are formed between the island-shaped oxide semiconductor layer and the source electrode and between the island-shaped oxide semiconductor layer and the drain electrode.

4. The photoelectric transducer device according to claim 1, wherein the converter circuit is a DC-DC converter.

5. The photoelectric transducer device according to claim 1, wherein the converter circuit is a DC-DC converter including a coil and a capacitor.

6. A photoelectric transducer device comprising:

a photoelectric transducer element; and

a converter circuit stepping up or stepping down an output of the photoelectric transducer element and including a switching element and a rectifier,

wherein the switching element is a first oxide semiconductor transistor that is normally off,

wherein the rectifier is a second oxide semiconductor transistor that is diode-connected and normally on, and

wherein a film thickness of a channel formation region of the first oxide semiconductor transistor is different from a film thickness of a channel formation region of the second oxide semiconductor transistor.

7. The photoelectric transducer device according to claim 6,

wherein the first oxide semiconductor transistor and the second oxide semiconductor transistor each comprise:

an island-shaped oxide semiconductor layer including the channel formation region;

a source electrode in contact with the island-shaped oxide semiconductor layer; and

a drain electrode in contact with the island-shaped oxide semiconductor layer, and

wherein a first region of the island-shaped oxide semiconductor layer having no overlap with the source electrode or the drain electrode is thinner than a second region of the island-shaped oxide semiconductor layer overlapping with the source electrode or the drain electrode.

8. The photoelectric transducer device according to claim 6,

wherein the first oxide semiconductor transistor and the second oxide semiconductor transistor each comprise:

an island-shaped oxide semiconductor layer including the channel formation region;

a source electrode over the island-shaped oxide semiconductor layer; and

a drain electrode over the island-shaped oxide semiconductor layer, and

wherein two oxide semiconductor layers having higher conductivity than the island-shaped oxide semiconductor layer are formed between the island-shaped oxide semiconductor layer and the source electrode and between the island-shaped oxide semiconductor layer and the drain electrode.

9. The photoelectric transducer device according to claim 6, wherein the converter circuit is a DC-DC converter.

10. The photoelectric transducer device according to claim 6, wherein the converter circuit is a DC-DC converter including a coil and a capacitor.

11. A photoelectric transducer device comprising:

a photoelectric transducer element; and

a converter circuit stepping up or stepping down an output of the photoelectric transducer element and including a switching element and a rectifier,

wherein the switching element is a first oxide semiconductor transistor that is normally off,

wherein the rectifier is a second oxide semiconductor transistor that is diode-connected and normally on, and

wherein a film thickness of a channel formation region of the first oxide semiconductor transistor is smaller than a film thickness of a channel formation region of the second oxide semiconductor transistor.

12. The photoelectric transducer device according to claim 11,

wherein the first oxide semiconductor transistor and the second oxide semiconductor transistor each comprise:

an island-shaped oxide semiconductor layer including the channel formation region;

a source electrode in contact with the island-shaped oxide semiconductor layer; and

a drain electrode in contact with the island-shaped oxide semiconductor layer, and

wherein a first region of the island-shaped oxide semiconductor layer having no overlap with the source electrode or the drain electrode is thinner than a second region of the island-shaped oxide semiconductor layer overlapping with the source electrode or the drain electrode.

13. The photoelectric transducer device according to claim 11,

wherein the first oxide semiconductor transistor and the second oxide semiconductor transistor each comprise:

an island-shaped oxide semiconductor layer including the channel formation region;

a source electrode over the island-shaped oxide semiconductor layer; and

a drain electrode over the island-shaped oxide semiconductor layer, and

wherein two oxide semiconductor layers having higher conductivity than the island-shaped oxide semiconductor layer are formed between the island-shaped oxide semiconductor layer and the source electrode and between the island-shaped oxide semiconductor layer and the drain electrode.

14. The photoelectric transducer device according to claim 11, wherein the converter circuit is a DC-DC converter.

15. The photoelectric transducer device according to claim 11, wherein the converter circuit is a DC-DC converter including a coil and a capacitor.

16. A photoelectric transducer device comprising:

a solar cell; and

a converter circuit stepping up or stepping down an output of the solar cell and including a switching element and a rectifier,

wherein the switching element is a first oxide semiconductor transistor that is normally off, and

wherein the rectifier is a second oxide semiconductor transistor that is diode-connected and normally on.

17. The photoelectric transducer device according to claim 16,

wherein the first oxide semiconductor transistor and the second oxide semiconductor transistor each comprise:

an island-shaped oxide semiconductor layer including a channel formation region;

a source electrode in contact with the island-shaped oxide semiconductor layer; and

a drain electrode in contact with the island-shaped oxide semiconductor layer, and

wherein a first region of the island-shaped oxide semiconductor layer having no overlap with the source electrode or the drain electrode is thinner than a second region of the island-shaped oxide semiconductor layer overlapping with the source electrode or the drain electrode.

18. The photoelectric transducer device according to claim 16,

wherein the first oxide semiconductor transistor and the second oxide semiconductor transistor each comprise:

an island-shaped oxide semiconductor layer including a channel formation region;

a source electrode over the island-shaped oxide semiconductor layer; and

a drain electrode over the island-shaped oxide semiconductor layer, and

wherein two oxide semiconductor layers having higher conductivity than the island-shaped oxide semiconductor layer are formed between the island-shaped oxide semiconductor layer and the source electrode and between the island-shaped oxide semiconductor layer and the drain electrode.

19. The photoelectric transducer device according to claim 16, wherein the converter circuit is a DC-DC converter.

20. The photoelectric transducer device according to claim 16, wherein the converter circuit is a DC-DC converter including a coil and a capacitor.

21. A photoelectric transducer device comprising:

a solar cell; and

a converter circuit stepping up or stepping down an output of the solar cell and including a switching element and a rectifier,

wherein the switching element is a first oxide semiconductor transistor that is normally off,

wherein the rectifier is a second oxide semiconductor transistor that is diode-connected and normally on, and

wherein a film thickness of a channel formation region of the first oxide semiconductor transistor is different from a film thickness of a channel formation region of the second oxide semiconductor transistor.

22. The photoelectric transducer device according to claim 21,

wherein the first oxide semiconductor transistor and the second oxide semiconductor transistor each comprise:

an island-shaped oxide semiconductor layer including the channel formation region;

a source electrode in contact with the island-shaped oxide semiconductor layer; and

a drain electrode in contact with the island-shaped oxide semiconductor layer, and

wherein a first region of the island-shaped oxide semiconductor layer having no overlap with the source electrode or the drain electrode is thinner than a second region of the island-shaped oxide semiconductor layer overlapping with the source electrode or the drain electrode.

23. The photoelectric transducer device according to claim 21,

wherein the first oxide semiconductor transistor and the second oxide semiconductor transistor each comprise:

an island-shaped oxide semiconductor layer including the channel formation region;

a source electrode over the island-shaped oxide semiconductor layer; and

a drain electrode over the island-shaped oxide semiconductor layer, and

wherein two oxide semiconductor layers having higher conductivity than the island-shaped oxide semiconductor layer are formed between the island-shaped oxide semiconductor layer and the source electrode and between the island-shaped oxide semiconductor layer and the drain electrode.

24. The photoelectric transducer device according to claim 21, wherein the converter circuit is a DC-DC converter.

25. The photoelectric transducer device according to claim 21, wherein the converter circuit is a DC-DC converter including a coil and a capacitor.

26. A photoelectric transducer device comprising:

a solar cell; and

a converter circuit stepping up or stepping down an output of the solar cell and including a switching element and a rectifier,

wherein the switching element is a first oxide semiconductor transistor that is normally off,

wherein the rectifier is a second oxide semiconductor transistor that is diode-connected and normally on, and

wherein a film thickness of a channel formation region of the first oxide semiconductor transistor is smaller than a film thickness of a channel formation region of the second oxide semiconductor transistor.

27. The photoelectric transducer device according to claim 26,

wherein the first oxide semiconductor transistor and the second oxide semiconductor transistor each comprise:

an island-shaped oxide semiconductor layer including the channel formation region;

a source electrode in contact with the island-shaped oxide semiconductor layer; and

a drain electrode in contact with the island-shaped oxide semiconductor layer, and

wherein a first region of the island-shaped oxide semiconductor layer having no overlap with the source electrode or the drain electrode is thinner than a second region of the island-shaped oxide semiconductor layer overlapping with the source electrode or the drain electrode.

28. The photoelectric transducer device according to claim 26,

wherein the first oxide semiconductor transistor and the second oxide semiconductor transistor each comprise:

an island-shaped oxide semiconductor layer including the channel formation region;

a source electrode over the island-shaped oxide semiconductor layer; and

a drain electrode over the island-shaped oxide semiconductor layer, and

wherein two oxide semiconductor layers having higher conductivity than the island-shaped oxide semiconductor layer are formed between the island-shaped oxide semiconductor layer and the source electrode and between the island-shaped oxide semiconductor layer and the drain electrode.

29. The photoelectric transducer device according to claim 26, wherein the converter circuit is a DC-DC converter.

30. The photoelectric transducer device according to claim 26, wherein the converter circuit is a DC-DC converter including a coil and a capacitor.