Reportable Segments - Schedule of Reportable Segment Information (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Sep. 30, 2023
Segment Reporting Information [Line Items]
Net Revenues		$ 26,749	$ 30,740	$ 77,102	$ 85,608
Operating income (loss)		816	(1,119)	(6,755)	(3,280)
Identifiable Assets		127,059		127,059		$ 137,021
Operating Segments | Semiconductor
Segment Reporting Information [Line Items]
Net Revenues		18,038	19,841	53,006	58,775
Operating income (loss)		1,690	1,042	3,666	4,861
Identifiable Assets		73,740		73,740		72,466
Operating Segments | Material and Substrate
Segment Reporting Information [Line Items]
Net Revenues		8,711	10,899	24,096	26,833
Operating income (loss)		1,621	481	(5,321)	1,411
Identifiable Assets		49,399		49,399		61,576
Non-Segment Related
Segment Reporting Information [Line Items]
Operating income (loss)		(2,495)	$ (2,642)	(5,100)	$ (9,552)
Identifiable Assets	[1]	$ 3,920		$ 3,920		$ 2,979

[1] * Non-segment related assets include cash, fixed assets, and other assets.