UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 31)*

Lighting Science Group Corporation

(Name of Issuer)

Common Stock, par value $.001 per share

(Title of Class of Securities)

53224G103

(CUSIP Number)

Steven Wacaster

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)

February 3, 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).

Amendment No. 31 to Schedule 13D

This Amendment No. 31 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 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 and Amendment No. 30 filed on January 15, 2014. Except as specifically provided herein, this Amendment No. 31 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 4 of Schedule 13D is supplemented and superseded, as the case may be, as follows:

On November 13, 2013, and December 4, 2013, the Issuer granted 26,301 and 14,795 shares of restricted common stock valued at
$0.48 per share and $0.44 per share, respectively, to Pegasus Capital Advisors IV, L.P. (“PCA IV”) as director fees in respect of Richard H. Davis Jr.’s (“Mr. Davis”) and Mr. Cogut’s Board service. The shares of restricted common stock granted in respect of Mr. Davis’ and Mr. Cogut’s Board service fully vested on January 1, 2014. Because Mr. Davis and Mr. Cogut, both partners of PCA IV or an affiliate thereof, serve on the Issuer’s Board as representatives of PCA IV and its affiliates, Mr. Davis and Mr. Cogut do not have a right to any of the Issuer’s securities issued as director fees and PCA IV is entitled to receive all director fees payable by the Issuer in respect of Mr. Davis’ and Mr. Cogut’s Board positions. All securities issued as director fees for Mr. Davis’ and Mr. Cogut’s Board service were accordingly issued directly to PCA IV. Pegasus Capital Advisors IV GP, LLC (“PCA IV GP”) is the general partner of PCA IV and Mr. Cogut is the sole owner and managing member of PCA IV GP.

On February 3, Mr. Davis, an affiliate and representative of PCA, PCA IV and their affiliates, was appointed Interim Chief Executive Officer of the Issuer. Mr. Davis has served as a member of the Issuer’s Board of Directors (the “Board”) since November 13, 2013. Additionally, on February 3, 2014 Philip Handy (“Mr. Handy”), a director previously designated by LSGC Holdings II, PCA Holdings and their affiliates, resigned from the Board and his position of Chairman of the Board and the Board appointed Jonathan Rosenbaum (“Mr. Rosenbaum”) to fill Mr. Handy’s vacancy. Mr. Rosenbaum was designated by LSGC Holdings II, PCA Holdings and their affiliates in connection the terms of the Series I Certificate of Designation and will serve until the next annual meeting of the Issuer’s stockholders or his earlier removal or resignation. As a result of Mr. Handy’s resignation, on February 3, 2014, the Board appointed Mr. Cogut, an affiliate and representative of PCA, PCA IV and their affiliates, and a current member of the Board, to serve as the Chairman of the Board. Steven Wacaster, a representative and affiliate of PCA, PCA IV and their affiliates, continues to serves as a director of the Issuer.

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.

Pursuant to the Series I Certificate of Designation, LSGC Holdings II, PCA Holdings and their affiliates currently may elect a portion of the Issuer’s board of directors of the Issuer equal to LSGC Holdings II’s, PCA Holdings’ and their affiliates’ proportionate share of the Issuer’s Common Stock on a fully diluted basis. In connection with the right to elect directors pursuant to the Series I Certificate of Designation, as amended, LSGC Holdings II, PCA Holdings and their affiliates may appoint the Chairman of the Issuer’s board of directors and additional directors to the Issuer’s board of directors.

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 207,845,587 shares of Common Stock outstanding as of February 5, 2014.

(c) The disclosure regarding the grant of 41,096 shares of the Issuer’s restricted common stock in Item 4 is incorporated by reference herein. 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

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: February 12, 2014

Exhibit 99.1

AGREEMENT REGARDING THE JOINT FILING OF SCHEDULE 13D

The accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended , the undersigned hereby confirm the agreement by and among them to the joint filing on behalf of them of a Statement on Schedule 13D and any and all amendments thereto with respect to the securities referenced in such statement, as amended, and that this Agreement be included as an Exhibit to such filing. This Agreement may be executed in any number of counterparts each of which shall be deemed to be an original and all of which together shall be deemed to constitute one and the same Agreement. Additionally, the undersigned hereby agree as follows:

(i) Each of them is individually eligible to use the Schedule 13D to which this Exhibit is attached, and such Schedule 13D is filed on behalf of each of them; and

(ii) Each of them is responsible for the timely filing of such Schedule 13D and any amendments thereto, and for the completeness and accuracy of the information concerning such person contained therein; but none of them is responsible for the completeness or accuracy of the information concerning the other persons making the filing, unless such person knows or has reason to believe that such information is inaccurate.

Date: February 12, 2014