<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2007-05-11</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001350102</issuerCik>
        <issuerName>Ascent Solar Technologies, Inc.</issuerName>
        <issuerTradingSymbol>ASTI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000704159</rptOwnerCik>
            <rptOwnerName>PAULSON CAPITAL CORP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>811 SW NAITO PARKWAY</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 200</rptOwnerStreet2>
            <rptOwnerCity>PORTLAND</rptOwnerCity>
            <rptOwnerState>OR</rptOwnerState>
            <rptOwnerZipCode>97204</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>See Footnote (1)</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000898196</rptOwnerCik>
            <rptOwnerName>PAULSON CHESTER L F</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>811 SW NAITO PARKWAY</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 200</rptOwnerStreet2>
            <rptOwnerCity>PORTLAND</rptOwnerCity>
            <rptOwnerState>OR</rptOwnerState>
            <rptOwnerZipCode>97204</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>See Footnote (1)</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000897686</rptOwnerCik>
            <rptOwnerName>PAULSON JACQUELINE M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>811 SW NAITO PARKWAY</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 200</rptOwnerStreet2>
            <rptOwnerCity>PORTLAND</rptOwnerCity>
            <rptOwnerState>OR</rptOwnerState>
            <rptOwnerZipCode>97204</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>See Footnote (1)</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Underwriter Warrants (Right to Buy Unit)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.60</value>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2007-07-10</value>
            </exerciseDate>
            <expirationDate>
                <value>2011-07-10</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>987600</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Form filed by more than one reporting person.  In addition to Paulson Capital Corp. (&quot;PLCC&quot;), the following are reporting parties: Chester L.F. Paulson, Jacqueline M. Paulson, Paulson Family LLC (&quot;LLC&quot;) and Paulson Investment Company, Inc. (&quot;PICI&quot;).  These reporting parties collectively own over 10%.  The address for each of the reporting parties is the same as that provided for PLCC.  PICI is a registered broker-dealer and a wholly owned subsidiary of PLCC.  Mr. and Mrs. Paulson are controlling managers of the LLC, which is a controlling shareholder of PLCC, which is the parent company of PICI.  Mr. and Mrs Paulson and the LLC expressly disclaim any beneficial ownership of securities held in the name of PLCC and PICI.</footnote>
        <footnote id="F2">The Reporting Persons own 246,900 Underwriter Warrants.  One (1) Underwriter Warrants is exercisable at $6.60 into one (1) Unit of Ascent Solar Technologies, Inc.  Each Unit consist of one (1) share of common stock, one (1) Class A Warrant and two (2) Class B Warrants.  Each Class A Warrant is exercisable at $6.60 into one (1) share of common stock and expire July 10, 2011.  Each Class B Warrant is exercisable at $11.00 into one (1) share of common stock and expire July 10, 2011.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Harry L. Striplin, Attorney-in-Fact for Chester L.F. Paulson</signatureName>
        <signatureDate>2007-05-14</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Harry L. Striplin, Authorized Agent for Paulson Capital Corp.</signatureName>
        <signatureDate>2007-05-14</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Harry L. Striplin, Authorized Agent for Paulson Investment Co., Inc.</signatureName>
        <signatureDate>2007-05-14</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Harry L. Striplin, Authorized Agent for Paulson Family LLC.</signatureName>
        <signatureDate>2007-05-14</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Harry L. Striplin, Attorney-in-Fact for Jacqueline M. Paulson</signatureName>
        <signatureDate>2007-05-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
