<PAGE>   1
                                                                    EXHIBIT 24.1

                           SI DIAMOND TECHNOLOGY, INC.
                                POWER OF ATTORNEY

            SI DIAMOND TECHNOLOGY, INC. ANNUAL REPORT ON FORM 10-KSB

        The undersigned, in his capacity as a director of SI Diamond Technology,
Inc. (the "Company"), after reviewing the Company's Form 10-KSB, does hereby
appoint Tracy Vaught, his true and lawful attorney to execute in his name, place
and stead, in his capacity as a Director of said Company, the Company's Annual
Report on Form 10-KSB for the fiscal year ended December 31, 1999, and all
instruments necessary or incidental in connection therewith, including all
amendments, and to file the same with the Securities and Exchange Commission.
Said attorney shall have the full power and authority to do and perform, in the
name and on behalf of the undersigned, in any and all capacities, every act
whatsoever requisite or necessary to be done in the premises, as fully and to
all intents and purposes as the undersigned might or could do in person, the
undersigned hereby ratifying and approving the acts of said attorney.

        IN TESTIMONY WHEREOF, the undersigned has executed this instrument this
21st day of March, 2000.





                             /s/ Phillip C. Shaffer
                             ----------------------
                             Philip C. Shaffer



<PAGE>   2


                                                                    EXHIBIT 24.2

                           SI DIAMOND TECHNOLOGY, INC.
                                POWER OF ATTORNEY

            SI DIAMOND TECHNOLOGY, INC. ANNUAL REPORT ON FORM 10-KSB

        The undersigned, in his capacity as a director of SI Diamond Technology,
Inc. (the "Company"), after reviewing the Company's Form 10-KSB, does hereby
appoint Tracy Vaught, his true and lawful attorney to execute in his name, place
and stead, in his capacity as a Director of said Company, the Company's Annual
Report on Form 10-KSB for the fiscal year ended December 31, 1999, and all
instruments necessary or incidental in connection therewith, including all
amendments, and to file the same with the Securities and Exchange Commission.
Said attorney shall have the full power and authority to do and perform, in the
name and on behalf of the undersigned, in any and all capacities, every act
whatsoever requisite or necessary to be done in the premises, as fully and to
all intents and purposes as the undersigned might or could do in person, the
undersigned hereby ratifying and approving the acts of said attorney.

        IN TESTIMONY WHEREOF, the undersigned has executed this instrument this
21st day of March, 2000.





                              /s/ David R. Sincox
                              -------------------
                              David R. Sincox



<PAGE>   3

                                                                    EXHIBIT 24.3

                           SI DIAMOND TECHNOLOGY, INC.
                                POWER OF ATTORNEY

            SI DIAMOND TECHNOLOGY, INC. ANNUAL REPORT ON FORM 10-KSB

        The undersigned, in his capacity as a director of SI Diamond Technology,
Inc. (the "Company"), after reviewing the Company's Form 10-KSB, does hereby
appoint Tracy Vaught, his true and lawful attorney to execute in his name, place
and stead, in his capacity as a Director of said Company, the Company's Annual
Report on Form 10-KSB for the fiscal year ended December 31, 1999, and all
instruments necessary or incidental in connection therewith, including all
amendments, and to file the same with the Securities and Exchange Commission.
Said attorney shall have the full power and authority to do and perform, in the
name and on behalf of the undersigned, in any and all capacities, every act
whatsoever requisite or necessary to be done in the premises, as fully and to
all intents and purposes as the undersigned might or could do in person, the
undersigned hereby ratifying and approving the acts of said attorney.

        IN TESTIMONY WHEREOF, the undersigned has executed this instrument this
21st day of March, 2000.





                            /s/ Nicholas Martin, Jr.
                            ------------------------
                            Nicholas Martin, Jr.



<PAGE>   4

                                                                    EXHIBIT 24.4

                           SI DIAMOND TECHNOLOGY, INC.
                                POWER OF ATTORNEY

            SI DIAMOND TECHNOLOGY, INC. ANNUAL REPORT ON FORM 10-KSB

        The undersigned, in his capacity as a director of SI Diamond Technology,
Inc. (the "Company"), after reviewing the Company's Form 10-KSB, does hereby
appoint Tracy Vaught, his true and lawful attorney to execute in his name, place
and stead, in his capacity as a Director of said Company, the Company's Annual
Report on Form 10-KSB for the fiscal year ended December 31, 1999, and all
instruments necessary or incidental in connection therewith, including all
amendments, and to file the same with the Securities and Exchange Commission.
Said attorney shall have the full power and authority to do and perform, in the
name and on behalf of the undersigned, in any and all capacities, every act
whatsoever requisite or necessary to be done in the premises, as fully and to
all intents and purposes as the undersigned might or could do in person, the
undersigned hereby ratifying and approving the acts of said attorney.

        IN TESTIMONY WHEREOF, the undersigned has executed this instrument this
21st day of March, 2000.





                              /s/ Ronald J. Berman
                              --------------------
                              Ronald J. Berman



<PAGE>   5

                                                                    EXHIBIT 24.5

                           SI DIAMOND TECHNOLOGY, INC.
                                POWER OF ATTORNEY

            SI DIAMOND TECHNOLOGY, INC. ANNUAL REPORT ON FORM 10-KSB

        The undersigned, in his capacity as a director of SI Diamond Technology,
Inc. (the "Company"), after reviewing the Company's Form 10-KSB, does hereby
appoint Tracy Vaught, his true and lawful attorney to execute in his name, place
and stead, in his capacity as a Director of said Company, the Company's Annual
Report on Form 10-KSB for the fiscal year ended December 31, 1999, and all
instruments necessary or incidental in connection therewith, including all
amendments, and to file the same with the Securities and Exchange Commission.
Said attorney shall have the full power and authority to do and perform, in the
name and on behalf of the undersigned, in any and all capacities, every act
whatsoever requisite or necessary to be done in the premises, as fully and to
all intents and purposes as the undersigned might or could do in person, the
undersigned hereby ratifying and approving the acts of said attorney.

        IN TESTIMONY WHEREOF, the undersigned has executed this instrument this
21st day of March, 2000.





                             /s/ Charles G. Bailey
                             ---------------------
                             Charles G. Bailey



<PAGE>   6

                                                                    EXHIBIT 24.6

                           SI DIAMOND TECHNOLOGY, INC.
                                POWER OF ATTORNEY

            SI DIAMOND TECHNOLOGY, INC. ANNUAL REPORT ON FORM 10-KSB

        The undersigned, in his capacity as a director of SI Diamond Technology,
Inc. (the "Company"), after reviewing the Company's Form 10-KSB, does hereby
appoint Tracy Vaught, his true and lawful attorney to execute in his name, place
and stead, in his capacity as a Director of said Company, the Company's Annual
Report on Form 10-KSB for the fiscal year ended December 31, 1999, and all
instruments necessary or incidental in connection therewith, including all
amendments, and to file the same with the Securities and Exchange Commission.
Said attorney shall have the full power and authority to do and perform, in the
name and on behalf of the undersigned, in any and all capacities, every act
whatsoever requisite or necessary to be done in the premises, as fully and to
all intents and purposes as the undersigned might or could do in person, the
undersigned hereby ratifying and approving the acts of said attorney.

        IN TESTIMONY WHEREOF, the undersigned has executed this instrument this
21st day of March, 2000.





                               /s/ Dr. Zvi Yaniv
                               -----------------
                               Dr. Zvi Yaniv