Morgan Sparks, who led Sandia National Laboratories for nearly a decade and created the first practical transistor, now found in every digital device, died Saturday. He was 91.

Sparks worked for 30 years at Bell Laboratories in New Jersey before taking over as director of Sandia in 1972. He served in the post until his retirement in 1981.

Sparks invented the first practical transistor, a semiconductor device that led to devices such as personal computers, cell phones, and DVD players.

Sparks joined the Semiconductor Research Group at the New Jersey lab in 1948 just as three of the group’s physicists — John Bardeen, Walter Brattain, and William Shockley — were developing the first transistor for which they won the Nobel Prize. The New Jersey lab is today the research arm of Alcatel-Lucent.

Sparks conducted materials science research with the group and worked with fellow team members Shockley and Gordon Teal to help develop the microwatt junction transistor in 1951.

Junction transistors began replacing vacuum tubes in electronic devices such as portable radios. Soon, transistors became essential in electronic computers and their production grew monumentally after the emergence of the microchip in the 1960s.

“They created a new field of science and new manifestations of matter. They were scientists who brought fundamental science to real world needs,” a spokesman for Bell Labs, Peter Benedict, said.

Sparks rose through the management ranks during the 1960s and 70s at Bell labs and the Western Electric Company — the manufacturing arm of American Telephone and Telegraph — before taking his position as director of Sandia.

The current director of Sandia, Tom Hunter, who was a young staff member at the lab when Sparks was director, Sparks said made a big impact.

“He set the framework for Sandia to become a multi-program lab. He was widely recognized for his ability to engage the labs in many new areas that proved to be important for our future,” Mr. Hunter said.

Sparks was active in civic life in Albuquerque following his retirement, serving on the boards of Presbyterian and Lovelace hospitals, the New Mexico Symphony Orchestra and Albuquerque Academy. He also was chairman of High Desert Investment Corporation until 2007.

The president of High Desert, Doug Collister, said Sparks — his friend for the last 30 years — had a rich group of friends he kept in contact with through his many endeavors.

Sparks often could be found joining in a round of golf while enjoying the warm New Mexico sunshine, Mr. Collister said.

“He was wise, thoughtful and kind, and he took his time and was not quick to rush to judgment. He had keen insights … it was an honor to have worked with him and to call him a friend,” Mr. Collister said. “I mean, it’s amazing when you think about the fact that he was there when the transistor was born. How do we live without them anymore?”

Senator Domenici, a Republican from New Mexico, said Sparks set a high standard of professional and efficient management at Sandia.

“He recognized the future need to channel lab science into technology transfer, and he laid the groundwork to link defense-based research to applications that now impact our lives every day,” Mr. Domenici said in a news release.

Sparks was born in 1916 in Pagosa Springs, Colo., and raised in Texas. He earned his bachelor’s and master’s degrees in chemistry at Rice University before receiving his doctorate in physical chemistry from the University of Illinois in 1943.

Morgan Sparks Jr. said his father rarely spoke of his scientific accomplishments.

“I knew my dad had something to do with [the transistor], but it was not until the whole culture went digital that his work became apparent.”