UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 36)*

Lighting Science Group Corporation

(Name of Issuer)

Common Stock, par value $.001 per share

(Title of Class of Securities)

53224G103

(CUSIP Number)

Daniel Stencel

LED Holdings, LLC

c\o Pegasus Capital Advisors, L.P.

99 River Road

Cos Cob, CT 06807

(203) 869-4400

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

August 7, 2014

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.  ¨

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7 for other parties to whom copies are to be sent.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP No. 53224G103

CUSIP No. 53224G103

CUSIP No. 53224G103

CUSIP No. 53224G103

CUSIP No. 53224G103

CUSIP No. 53224G103

CUSIP No. 53224G103

CUSIP No. 53224G103

CUSIP No. 53224G103

CUSIP No. 53224G103

CUSIP No. 53224G103

Amendment No. 36 to Schedule 13D

This Amendment No. 36 amends and supplements the Schedule 13D (the “Schedule 13D”) filed on behalf of LED Holdings, LLC (“LED Holdings”), Pegasus Capital Advisors, L.P. (“PCA”), Pegasus Capital Advisors GP, L.L.C. (“PCA GP”), PP IV (AIV) LED, LLC (“PPAIV”), PP IV LED, LLC (“PPLED”), Pegasus Partners IV, L.P. (“PPIV”), LSGC Holdings LLC (“LSGC Holdings”), LSGC Holdings II LLC (“LSGC Holdings II”), PCA LSG Holdings, LLC (“PCA Holdings”) Pegasus Investors IV, L.P. (“PIIV”), Pegasus Investors IV GP, L.L.C. (“PIGP”), Pegasus Capital, LLC (“PCLLC”), and Craig Cogut (“Mr. Cogut,” and together with LED Holdings, PPAIV, PPLED, PPIV, LSGC Holdings, LSGC Holdings II, PCA Holdings, PIIV, PIGP and PCLLC, the “Reporting Persons”) with the Securities and Exchange Commission (the “SEC”), as the case may be, on October 15, 2007, as amended by Amendment No. 1 filed on April 11, 2008, Amendment No. 2 filed on May 1, 2008, Amendment No. 3 filed on July 30, 2008, Amendment No. 4 filed on January 12, 2009, Amendment No. 5 filed on February 20, 2009, Amendment No. 6 filed on May 22, 2009, Amendment No. 7 filed on August 17, 2009, Amendment No. 8 filed on September 1, 2009, Amendment No. 9 filed on March 8, 2010, Amendment No. 10 filed on March 24, 2010, Amendment No. 11 filed on April 28, 2010, Amendment No. 12 filed on May 14, 2010, Amendment No. 13 filed on July 2, 2010, Amendment No. 14 filed on July 16, 2010, Amendment No. 15 filed on November 5, 2010, Amendment No. 16 filed on December 28, 2010, Amendment No. 17 filed on February 2, 2011, Amendment No. 18 filed on February 18, 2011, Amendment No. 19 filed on May 26, 2011, Amendment No. 20 filed on December 13, 2011, Amendment No. 21 filed on December 23, 2011, Amendment No. 22 filed on January 30, 2012, Amendment No. 23 filed on April 4, 2012, Amendment No. 24 filed on April 24, 2012, Amendment No. 25 filed on May 31, 2012, Amendment No. 26 filed on October 1, 2012, Amendment No. 27 filed on September 17, 2013, Amendment No. 28 filed on December 5, 2013, Amendment No. 29 filed on January 8, 2014, Amendment No. 30 filed on January 15, 2014, Amendment No. 31 filed on February 12, 2014, Amendment No. 32 filed on February 21, 2014, Amendment No. 33 filed on April 7, 2014, Amendment No. 34 filed on June 23, 2014, and Amendment No. 35 filed on August 4, 2014. Except as specifically provided herein, this Amendment No. 36 supplements, but does not modify any of the disclosure previously reported in the Schedule 13D and the amendments referenced above. Each capitalized term used but not defined herein has the meaning ascribed to such term in the Schedule 13D, as amended.

Item 3 of Schedule 13D is supplemented as follows:

The disclosure in Item 4 below is incorporated by reference herein.

Item 4 of Schedule 13D is supplemented and superseded, as the case may be, as follows:

Series J Subscription Agreement

On August 14, 2014, Lighting Science Group Corporation (the “Issuer”) entered into a Series J Subscription Agreement (the “Series J Subscription Agreement”) with PCA Holdings. On August 14, 2014, pursuant to the Series J Subscription Agreement, the Issuer issued 2,000 units of its securities (the “Series J Securities”) to PCA Holdings at a price of $1,000 per Series J Security and total consideration of $2,000,000. Each Series J Security consists of (A) one share of the Issuer’s Series J Convertible Preferred Stock, par value $0.001 per share (the “Series J Preferred Stock”) and (B) a warrant to purchase 2,650 shares of the Issuer’s common stock, at an exercise price of $0.001 per share (the “Warrants”). The designations, powers, rights, and preferences of the Series J Preferred Stock are governed by the Amended and Restated Certificate of Designation governing the Series J Preferred Stock (the “Series J Certificate of Designation”). The Warrants issued to PCA Holdings as part of the Series J Securities contain substantially identical terms as the warrants previously issued to PCA Holdings on January 3, 2014, and filed as Exhibit 4.5 to the Issuer’s Form 8-K filed with the SEC on January 8, 2014.

On August 7, 2014, and in connection with the transactions contemplated by the Series J Subscription Agreement, PCA, PCA Holdings and LSGC Holdings II (collectively, “Pegasus”), and RW LSG Holdings, LLC and its affiliates (“Riverwood”), as the “Primary Investors” of the Issuer’s Series H Convertible Preferred Stock (the “Series H Preferred Stock”) and Series I Convertible Preferred Stock (the “Series I Preferred Stock”), respectively, and as the joint “Primary Investors” of the Series J Preferred Stock, consented to: (1) the Issuer’s issuance and sale of up to 30,000 Series J Securities on or before December 31, 2014 and (2) the amendment and restatement of the Certificates of Designation governing the Series H Preferred Stock, the Series I Preferred Stock and the Series J Preferred Stock. Accordingly, the Series J Subscription Agreement provides that the Company is permitted (without further approval from Pegasus or Riverwood), on or before December 31, 2014, to issue up to an additional 28,000 Series J Securities (for an aggregate total of 30,000 Series J Securities) to any persons approved by the Issuer (such offering, the “Series J Offering”). Pursuant to this provision, on August 20, 2014, the Issuer issued an additional 2,000 Series J Securities to PCA Holdings and received an additional $2,000,000 in total consideration for such Series J Securities (for aggregate proceeds to the Issuer of $4,000,000 pursuant to the Series J Offering as of August 20, 2014).

The foregoing description of the Series J Subscription Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of the Series J Subscription Agreement, which is incorporated by reference as Exhibit 10.1, and is incorporated herein by reference.

In connection with the Series J Offering, and in accordance with the Series J Certificate of Designation, the Amended and Restated Certificate of Designation governing the Issuer’s Series H Preferred Stock (the “Series H Certificate of Designation”) and the Amended and Restated Certificate of Designation governing the Issuer’s Series I Preferred Stock (the “Series I Certificate of Designation,” and together with the Series H Certificate of Designation and Series J Certificate of Designation, the “Certificates of Designation”), the Issuer is required to offer to all holders of shares of the Issuer’s Series H Preferred Stock, Series I Preferred Stock and Series J Preferred Stock, the right to purchase a pro rata amount of the shares of the Series J Securities issued pursuant to the Series J Offering (based upon such holder’s ownership of the Issuer’s outstanding shares of common stock on a fully diluted, as converted basis).

Amendments to Certificates of Designation

On August 14, 2014, and in connection with the transactions contemplated by the Series J Offering, the Issuer amended and restated the Series J Certificate of Designation and the Certificates of Designation governing the Series H and Series I Preferred Stock (collectively, the “Amended Certificates of Designation”). The Amended Certificates of Designation amend the terms of the Certificates of Designation to, among other things, (i) reinsert a covenant requiring the Issuer to obtain the consent of Riverwood and Pegasus as the “Primary Investors” of the Series H Preferred Stock and Series I Preferred Stock, respectively, and as the joint “Primary Investors” of the Series J Preferred Stock, prior to the Issuer’s appointment of a new, removal of the then-current, or determination or modification of any compensation for the Chief Executive Officer, Chief Operating Officer, Chief Financial Officer or Chief Technology Officer (or equivalents thereof) and (ii) make certain other clarifying amendments to the Certificates of Designation.

The Reporting Persons refer you to the Issuer’s Form 8-K filed with the SEC on August 20, 2014, for the full texts of the Series J Certificate of Designation, Amended and Restated Certificate of Designation governing the Series H Preferred Stock and the Amended and Restated Certificate of Designation governing the Series I Preferred Stock, attached thereto as Exhibits 4.1, 4.2 and 4.3, respectively.

The Reporting Persons continuously assess the Issuer’s business, financial condition, results of operations and prospects, general economic conditions, other developments and additional investment opportunities. Depending on such assessments, the Reporting Persons and/or their affiliates may acquire additional securities of the Issuer, including but not limited to common stock, existing preferred securities or new securities of the Issuer or may determine to purchase, sell or otherwise dispose of all or some of the Issuer’s securities in the open market, as applicable, in privately negotiated transactions, in transactions directly with the Issuer or otherwise. Such actions will depend upon a variety of factors, including, without limitation, current and anticipated future trading prices, the financial condition, results of operations and prospects of the Issuer, alternative investment opportunities, general economic, financial market and industry conditions and other factors that the Reporting Persons and/or their affiliates may deem material to its investment decision. Also, the Reporting Persons and/or their affiliates have had and will continue to have discussions with management regarding the operations of the Issuer and matters of mutual interest, which could include the items in subparagraphs (a) through (j) of Item 4 of Schedule 13D.

Except as set forth herein and/or in previous amendments to this Schedule 13D, as the case may be, the Reporting Persons do not have present plans or proposals at this time that relate to or would result in any of the transactions described in subparagraphs (a) through (j) of Item 4 of Schedule 13D.

Item 5 of this Schedule 13D is hereby amended and restated in its entirety as follows:

(a) (b) Items 7 through 11 and 13 of each of the cover pages of this amended Schedule 13D are incorporated herein by reference. Such information is based upon 209,606,581 shares of common stock outstanding as of August 14, 2014.

(c) Except as set forth herein and/or in our previously filed amendments to Schedule 13D, as the case may be, there have been no other transactions in the class of securities reported on that were effected within the past 60 days.

(d) The disclosure regarding the relationship between the Reporting Persons in Item 2(f) of Amendment No. 28 to this Schedule 13D is incorporated by reference herein.

(e) N/A

The disclosure in Item 4 is incorporated by reference herein.

The Series J Subscription Agreement is incorporated by reference as Exhibit 10.1 to this Amendment No. 36 to Schedule 13D and is incorporated by reference herein.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: August 20, 2014