Exhibit 5.1

Morgan, Lewis & Bockius LLP
Counselors at Law

1701 Market Street
Philadelphia, PA 19103-2921
215-963-5000
Fax: 215-963-5299

                                                     May 23, 2002

Universal Display Corporation
375 Phillips Boulevard
Ewing, NJ  08618

Re:      Universal Display Corporation
         Registration Statement on Form S-3
         ----------------------------------

Ladies and Gentlemen:

We have acted as counsel for Universal Display Corporation, a Pennsylvania
corporation (the "Company"), in connection with the Registration Statement on
Form S-3 (the "Registration Statement") under the Securities Act of 1933, as
amended (the "Act"), relating to the proposed offer and sale by the Company from
time to time, as set forth in the prospectus contained in the Registration
Statement (the "Prospectus") and as shall be set forth in one or more
supplements to the Prospectus (each, a "Prospectus Supplement"), of up to
$50,000,000 aggregate offering price of securities (the "Securities") which may
include any or all of (i) shares of Common Stock, par value $0.01 per share, of
the Company (the "Common Stock"), (ii) shares of Preferred Stock, par value
$0.01 per share, of the Company (the "Preferred Stock"), (iii) warrants to
purchase Common Stock or Preferred Stock (the "Warrants") and (iv) depositary
shares representing fractional shares of Preferred Stock (the "Depositary
Shares").

In connection with this opinion, we have examined a copy of (1) the Registration
Statement; (2) the Company's Articles of Incorporation, as amended (the
"Articles"); (3) the Company's Bylaws, as amended (the "Bylaws"); (4) certain
resolutions of the Company's Board of Directors relating to the Registration
Statement, and (5) such other documents as we have deemed appropriate. In our
examination, we have assumed the genuineness of all signatures, the authenticity
of all documents submitted to us as originals, and the conformity to authentic
original documents of all documents submitted to us as copies. With respect to
matters of fact relevant to our opinion, we have relied upon certificates of
officers of the Company, representations made by the Company in other documents
examined by us and other representations of officers of the Company. We have
also obtained and relied upon such certificates and assurances from public
officials as we have deemed necessary.

For the purpose of the opinions set forth below, we have assumed, without
independent investigation, that (1) the issuance, sale, number and terms of
Securities to be offered from time to time will be duly authorized and
established, in accordance with the Articles, the Bylaws and applicable
Pennsylvania law (each, a "Board Action"); (2) prior to any issuance of shares
of a class or series of Preferred Stock, an appropriate statement with respect
to shares relating to such class or series of Preferred Stock will have been
duly authorized by Board Action and filed with the Department of State of the
Commonwealth of Pennsylvania; (3) any Warrants will be issued under one or more
warrant agreements (each, a "Warrant Agreement") between the Company and a
financial institution identified in the Warrant Agreement as a warrant agent
(each, a "Warrant Agent"); (4) any Depositary Shares will be issued under one or
more deposit agreements (each, a "Deposit Agreement") between the Company and a
financial institution identified in the Deposit Agreement as a depositary (each,
a "Depositary");(5) the Registration Statement and any post-effective amendments
thereto will have become effective and comply with all applicable laws; (6) the
Registration Statement and any post-effective amendments thereto will be
effective and will comply with all applicable laws at the time the Securities
are offered or issued as contemplated by the Registration Statement; (7) a
Prospectus Supplement or term sheet will have been prepared and filed with the
Securities and Exchange Commission describing the Securities offered thereby and
will comply with all applicable laws; (8) all Securities will be issued and sold
in compliance with all applicable laws; and (9) a definitive purchase,
underwriting or similar agreement with respect to any Securities offered or
issued will have been duly authorized and validly executed and delivered by the
Company and the other parties thereto.


Subject to the foregoing and the other matters set forth herein, it is our
opinion that, as of the date hereof:

1. Upon due authorization by Board Action of the issuance and sale of shares of
the Common Stock and upon issuance and delivery of such shares of Common Stock
against payment for such shares in accordance with the terms of the Board Action
and as contemplated by the Registration Statement and the applicable Prospectus
Supplement, and, if applicable, upon the exercise of any Warrants or conversion
of any Preferred Stock in accordance with their respective terms, such shares of
Common Stock will be validly issued, fully paid and nonassessable.

2. Upon due authorization by Board Action of the issuance and sale of shares of
a class or series of Preferred Stock (including Preferred Stock represented by
Depositary Shares) and upon issuance and delivery of such shares of Preferred
Stock against payment for such shares in accordance with the terms of the Board
Action and as contemplated by the Registration Statement and the applicable
Prospectus Supplement, and, if applicable, upon the exercise of any Warrants in
accordance with its terms, such shares of such class or series of Preferred
Stock will be validly issued, fully paid and nonassessable.

3. When a Warrant Agreement providing for the specific terms of a particular
issuance of Warrants has been duly authorized by Board Action and has been duly
executed and delivered by the Company and the Warrant Agent named in the Warrant
Agreement, and Warrants conforming to the requirements of the related Warrant
Agreement have been duly countersigned or authenticated, as required, by the
Warrant Agent and duly executed and delivered by the Company against payment for
such Warrants in accordance with the terms of the Warrant Agreement and as
contemplated by the Registration Statement and the applicable Prospectus
Supplement, such Warrants will constitute valid and binding obligations of the
Company.



4. When a Deposit Agreement providing for the specific terms of a particular
issuance of Depositary Shares has been duly authorized by Board Action and has
been duly executed and delivered by the Company and the Depositary named in the
Deposit Agreement and the terms of the shares of Preferred Stock represented by
such Depositary Shares and of their issuance and sale have been duly established
in conformity with such Deposit Agreement, the shares of Preferred Stock
represented by such Depositary Shares are validly issued and delivered to the
Depositary under the terms of such Deposit Agreement, the depositary receipts
evidencing the Depositary Shares are duly executed and authenticated in
accordance with such Deposit Agreement and delivered against payment for such
Depositary Shares in accordance with the terms of the Deposit Agreement and as
contemplated by the Registration Statement and the applicable Prospectus
Supplement, such Depositary Shares will be validly issued and said depositary
receipts will entitle the holders thereof to the rights specified therein and in
the Deposit Agreement.

To the extent that the obligations of the Company under each Warrant Agreement
may be dependent upon such matters, we assume for purposes of this opinion that
the Warrant Agent is duly organized, validly existing and in good standing under
the laws of its jurisdiction of organization; that the Warrant Agent is duly
qualified to engage in the activities contemplated by the Warrant Agreement;
that the Warrant Agreement has been duly authorized, executed and delivered by
the Warrant Agent and constitutes the legal, valid and binding obligation of the
Warrant Agent, enforceable against the Warrant Agent in accordance with its
terms; that the Warrant Agent is in compliance, generally and with respect to
acting as a Warrant Agent under the Warrant Agreement, with all applicable laws
and regulations; and that the Warrant Agent has the requisite organizational and
legal power and authority to perform its obligations under the Warrant
Agreement.

To the extent that the obligations of the Company under each Deposit Agreement
may be dependent upon such matters, we assume for purposes of this opinion that
the Depositary is duly organized, validly existing and in good standing under
the laws of its jurisdiction of organization; that the Depositary is duly
qualified to engage in the activities contemplated by the Deposit Agreement;
that the Deposit Agreement has been duly authorized, executed and delivered by
the Depositary and constitutes the legal, valid and binding obligation of the
Depositary, enforceable against the Depositary in accordance with its terms;
that the Depositary is in compliance, generally and with respect to acting as a
Depositary under the Deposit Agreement, with all applicable laws and
regulations; and that the Depositary has the requisite organizational and legal
power and authority to perform its obligations under the Deposit Agreement.

The opinions set forth in clauses 3 and 4 above are subject to the following
exceptions, limitations and qualifications: (i) the effect of bankruptcy,
insolvency, reorganization, fraudulent conveyance, moratorium or other similar
laws now or hereafter in effect relating to or affecting the rights or remedies
of creditors; (ii) the effect of general principles of equity, whether
enforcement is considered in a proceeding in equity or at law, and the
discretion of the court before which any proceeding therefor may be brought; and
(iii) the unenforceability under certain circumstances under law or court
decisions of provisions providing for the indemnification of or contribution to
a party with respect to a liability where such indemnification or contribution
is contrary to public policy.

The foregoing opinions are limited to the laws of the Commonwealth of
Pennsylvania.

We consent to your filing this opinion as an exhibit to the Registration
Statement and to the reference to our firm under the caption "Legal Matters" in
the prospectus included therein. In giving such opinion, we do not hereby admit
that we are acting within the category of persons whose consent is required
under Section 7 of the Act or the rules or regulations of the Securities and
Exchange Commission thereunder.

Very truly yours,


/s/ Morgan, Lewis & Bockius LLP